Internet Research Task Force (IRTF) R.L. Barnes Internet-Draft Cisco Intended status: Informational K. Bhargavan Expires: 27 November 2021 B. Lipp Inria C.A. Wood Cloudflare 26 May 2021 Hybrid Public Key Encryption draft-irtf-cfrg-hpke-09 Abstract This document describes a scheme for hybrid public-key encryption (HPKE). This scheme provides authenticated public key encryption of arbitrary-sized plaintexts for a recipient public key. HPKE works for any combination of an asymmetric key encapsulation mechanism (KEM), key derivation function (KDF), and authenticated encryption with additional data (AEAD) encryption function. We provide instantiations of the scheme using widely used and efficient primitives, such as Elliptic Curve Diffie-Hellman key agreement, HKDF, and SHA2. This document is a product of the Crypto Forum Research Group (CFRG) in the IRTF. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 27 November 2021. Barnes, et al. Expires 27 November 2021 [Page 1] Internet-Draft HPKE May 2021 Copyright Notice Copyright (c) 2021 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Requirements Notation . . . . . . . . . . . . . . . . . . . . 5 3. Notation . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Cryptographic Dependencies . . . . . . . . . . . . . . . . . 6 4.1. DH-Based KEM . . . . . . . . . . . . . . . . . . . . . . 8 5. Hybrid Public Key Encryption . . . . . . . . . . . . . . . . 11 5.1. Creating the Encryption Context . . . . . . . . . . . . . 12 5.1.1. Encryption to a Public Key . . . . . . . . . . . . . 15 5.1.2. Authentication using a Pre-Shared Key . . . . . . . . 15 5.1.3. Authentication using an Asymmetric Key . . . . . . . 16 5.1.4. Authentication using both a PSK and an Asymmetric Key . . . . . . . . . . . . . . . . . . . . . . . . . 16 5.2. Encryption and Decryption . . . . . . . . . . . . . . . . 17 5.3. Secret Export . . . . . . . . . . . . . . . . . . . . . . 19 6. Single-Shot APIs . . . . . . . . . . . . . . . . . . . . . . 19 6.1. Encryption and Decryption . . . . . . . . . . . . . . . . 19 6.2. Secret Export . . . . . . . . . . . . . . . . . . . . . . 20 7. Algorithm Identifiers . . . . . . . . . . . . . . . . . . . . 20 7.1. Key Encapsulation Mechanisms (KEMs) . . . . . . . . . . . 21 7.1.1. SerializePublicKey and DeserializePublicKey . . . . . 21 7.1.2. SerializePrivateKey and DeserializePrivateKey . . . . 22 7.1.3. DeriveKeyPair . . . . . . . . . . . . . . . . . . . . 22 7.1.4. Validation of Inputs and Outputs . . . . . . . . . . 24 7.1.5. KEM Key Reuse . . . . . . . . . . . . . . . . . . . . 24 7.1.6. Future KEMs . . . . . . . . . . . . . . . . . . . . . 24 7.2. Key Derivation Functions (KDFs) . . . . . . . . . . . . . 25 7.2.1. Input Length Restrictions . . . . . . . . . . . . . . 25 7.3. Authenticated Encryption with Associated Data (AEAD) Functions . . . . . . . . . . . . . . . . . . . . . . . . 27 8. API Considerations . . . . . . . . . . . . . . . . . . . . . 27 9. Security Considerations . . . . . . . . . . . . . . . . . . . 28 9.1. Security Properties . . . . . . . . . . . . . . . . . . . 28 Barnes, et al. Expires 27 November 2021 [Page 2] Internet-Draft HPKE May 2021 9.1.1. Key-Compromise Impersonation . . . . . . . . . . . . 29 9.1.2. Computational Analysis . . . . . . . . . . . . . . . 30 9.1.3. Post-Quantum Security . . . . . . . . . . . . . . . . 32 9.2. Security Requirements on a KEM used within HPKE . . . . . 33 9.2.1. Encap/Decap Interface . . . . . . . . . . . . . . . . 33 9.2.2. AuthEncap/AuthDecap Interface . . . . . . . . . . . . 33 9.3. Security Requirements on a KDF . . . . . . . . . . . . . 34 9.4. Pre-Shared Key Recommendations . . . . . . . . . . . . . 34 9.5. Domain Separation . . . . . . . . . . . . . . . . . . . . 34 9.6. Application Embedding . . . . . . . . . . . . . . . . . . 35 9.6.1. External Requirements . . . . . . . . . . . . . . . . 35 9.6.2. Non-Goals . . . . . . . . . . . . . . . . . . . . . . 36 9.7. Bidirectional Encryption . . . . . . . . . . . . . . . . 36 9.8. Metadata Protection . . . . . . . . . . . . . . . . . . . 37 10. Message Encoding . . . . . . . . . . . . . . . . . . . . . . 38 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38 11.1. KEM Identifiers . . . . . . . . . . . . . . . . . . . . 38 11.2. KDF Identifiers . . . . . . . . . . . . . . . . . . . . 39 11.3. AEAD Identifiers . . . . . . . . . . . . . . . . . . . . 39 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 40 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 40 13.1. Normative References . . . . . . . . . . . . . . . . . . 40 13.2. Informative References . . . . . . . . . . . . . . . . . 40 Appendix A. Test Vectors . . . . . . . . . . . . . . . . . . . . 44 A.1. DHKEM(X25519, HKDF-SHA256), HKDF-SHA256, AES-128-GCM . . 44 A.1.1. Base Setup Information . . . . . . . . . . . . . . . 44 A.1.2. PSK Setup Information . . . . . . . . . . . . . . . . 47 A.1.3. Auth Setup Information . . . . . . . . . . . . . . . 49 A.1.4. AuthPSK Setup Information . . . . . . . . . . . . . . 51 A.2. DHKEM(X25519, HKDF-SHA256), HKDF-SHA256, ChaCha20Poly1305 . . . . . . . . . . . . . . . . . . . . 53 A.2.1. Base Setup Information . . . . . . . . . . . . . . . 53 A.2.2. PSK Setup Information . . . . . . . . . . . . . . . . 55 A.2.3. Auth Setup Information . . . . . . . . . . . . . . . 57 A.2.4. AuthPSK Setup Information . . . . . . . . . . . . . . 59 A.3. DHKEM(P-256, HKDF-SHA256), HKDF-SHA256, AES-128-GCM . . . 61 A.3.1. Base Setup Information . . . . . . . . . . . . . . . 61 A.3.2. PSK Setup Information . . . . . . . . . . . . . . . . 63 A.3.3. Auth Setup Information . . . . . . . . . . . . . . . 65 A.3.4. AuthPSK Setup Information . . . . . . . . . . . . . . 67 A.4. DHKEM(P-256, HKDF-SHA256), HKDF-SHA512, AES-128-GCM . . . 69 A.4.1. Base Setup Information . . . . . . . . . . . . . . . 69 A.4.2. PSK Setup Information . . . . . . . . . . . . . . . . 71 A.4.3. Auth Setup Information . . . . . . . . . . . . . . . 73 A.4.4. AuthPSK Setup Information . . . . . . . . . . . . . . 76 A.5. DHKEM(P-256, HKDF-SHA256), HKDF-SHA256, ChaCha20Poly1305 . . . . . . . . . . . . . . . . . . . . 79 A.5.1. Base Setup Information . . . . . . . . . . . . . . . 79 Barnes, et al. Expires 27 November 2021 [Page 3] Internet-Draft HPKE May 2021 A.5.2. PSK Setup Information . . . . . . . . . . . . . . . . 81 A.5.3. Auth Setup Information . . . . . . . . . . . . . . . 83 A.5.4. AuthPSK Setup Information . . . . . . . . . . . . . . 85 A.6. DHKEM(P-521, HKDF-SHA512), HKDF-SHA512, AES-256-GCM . . . 87 A.6.1. Base Setup Information . . . . . . . . . . . . . . . 87 A.6.2. PSK Setup Information . . . . . . . . . . . . . . . . 90 A.6.3. Auth Setup Information . . . . . . . . . . . . . . . 93 A.6.4. AuthPSK Setup Information . . . . . . . . . . . . . . 96 A.7. DHKEM(X25519, HKDF-SHA256), HKDF-SHA256, Export-Only AEAD . . . . . . . . . . . . . . . . . . . . . . . . . . 99 A.7.1. Base Setup Information . . . . . . . . . . . . . . . 99 A.7.2. PSK Setup Information . . . . . . . . . . . . . . . . 100 A.7.3. Auth Setup Information . . . . . . . . . . . . . . . 101 A.7.4. AuthPSK Setup Information . . . . . . . . . . . . . . 102 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 103 1. Introduction Encryption schemes that combine asymmetric and symmetric algorithms have been specified and practiced since the early days of public-key cryptography, e.g., [RFC1421]. Combining the two yields the key management advantages of asymmetric cryptography and the performance benefits of symmetric cryptography. The traditional combination has been "encrypt the symmetric key with the public key." "Hybrid" public-key encryption schemes (HPKE), specified here, take a different approach: "generate the symmetric key and its encapsulation with the public key." Specifically, encrypted messages convey an encryption key encapsulated with a public-key scheme, along with one or more arbitrary-sized ciphertexts encrypted using that key. This type of public key encryption has many applications in practice, including Messaging Layer Security [I-D.ietf-mls-protocol] and TLS Encrypted ClientHello [I-D.ietf-tls-esni]. Currently, there are numerous competing and non-interoperable standards and variants for hybrid encryption, mostly based on ECIES, including ANSI X9.63 (ECIES) [ANSI], IEEE 1363a [IEEE1363], ISO/IEC 18033-2 [ISO], and SECG SEC 1 [SECG]. See [MAEA10] for a thorough comparison. All these existing schemes have problems, e.g., because they rely on outdated primitives, lack proofs of IND-CCA2 security, or fail to provide test vectors. This document defines an HPKE scheme that provides a subset of the functions provided by the collection of schemes above, but specified with sufficient clarity that they can be interoperably implemented. The HPKE construction defined herein is secure against (adaptive) chosen ciphertext attacks (IND-CCA2 secure) under classical assumptions about the underlying primitives [HPKEAnalysis], [ABHKLR20]. A summary of these analyses is in Section 9.1. Barnes, et al. Expires 27 November 2021 [Page 4] Internet-Draft HPKE May 2021 This document represents the consensus of the Crypto Forum Research Group (CFRG). 2. Requirements Notation The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. Notation The following terms are used throughout this document to describe the operations, roles, and behaviors of HPKE: * "(skX, pkX)": A Key Encapsulation Mechanism (KEM) key pair used in role X, where X is one of S, R, or E as sender, recipient, and ephemeral, respectively; "skX" is the private key and "pkX" is the public key. * "pk(skX)": The KEM public key corresponding to the KEM private key "skX". * Sender (S): Role of entity which sends an encrypted message. * Recipient (R): Role of entity which receives an encrypted message. * Ephemeral (E): Role of a fresh random value meant for one-time use. * "I2OSP(n, w)": Convert non-negative integer "n" to a "w"-length, big-endian byte string as described in [RFC8017]. * "OS2IP(x)": Convert byte string "x" to a non-negative integer as described in [RFC8017], assuming big-endian byte order. * "concat(x0, ..., xN)": Concatenation of byte strings. "concat(0x01, 0x0203, 0x040506) = 0x010203040506". * "random(n)": A pseudorandom byte string of length "n" bytes * "xor(a,b)": XOR of byte strings; "xor(0xF0F0, 0x1234) = 0xE2C4". It is an error to call this function with two arguments of unequal length. Barnes, et al. Expires 27 November 2021 [Page 5] Internet-Draft HPKE May 2021 4. Cryptographic Dependencies HPKE variants rely on the following primitives: * A Key Encapsulation Mechanism (KEM): - "GenerateKeyPair()": Randomized algorithm to generate a key pair "(skX, pkX)". - "DeriveKeyPair(ikm)": Deterministic algorithm to derive a key pair "(skX, pkX)" from the byte string "ikm", where "ikm" SHOULD have at least "Nsk" bytes of entropy (see Section 7.1.3 for discussion). - "SerializePublicKey(pkX)": Produce a byte string of length "Npk" encoding the public key "pkX". - "DeserializePublicKey(pkXm)": Parse a byte string of length "Npk" to recover a public key. This function can raise a "DeserializeError" error upon "pkXm" deserialization failure. - "Encap(pkR)": Randomized algorithm to generate an ephemeral, fixed-length symmetric key (the KEM shared secret) and a fixed- length encapsulation of that key that can be decapsulated by the holder of the private key corresponding to "pkR". - "Decap(enc, skR)": Deterministic algorithm using the private key "skR" to recover the ephemeral symmetric key (the KEM shared secret) from its encapsulated representation "enc". This function can raise a "DecapError" on decapsulation failure. - "AuthEncap(pkR, skS)" (optional): Same as "Encap()", and the outputs encode an assurance that the KEM shared secret was generated by the holder of the private key "skS". - "AuthDecap(enc, skR, pkS)" (optional): Same as "Decap()", and the recipient is assured that the KEM shared secret was generated by the holder of the private key "skS". - "Nsecret": The length in bytes of a KEM shared secret produced by this KEM. - "Nenc": The length in bytes of an encapsulated key produced by this KEM. - "Npk": The length in bytes of an encoded public key for this KEM. Barnes, et al. Expires 27 November 2021 [Page 6] Internet-Draft HPKE May 2021 - "Nsk": The length in bytes of an encoded private key for this KEM. * A Key Derivation Function (KDF): - "Extract(salt, ikm)": Extract a pseudorandom key of fixed length "Nh" bytes from input keying material "ikm" and an optional byte string "salt". - "Expand(prk, info, L)": Expand a pseudorandom key "prk" using optional string "info" into "L" bytes of output keying material. - "Nh": The output size of the "Extract()" function in bytes. * An AEAD encryption algorithm [RFC5116]: - "Seal(key, nonce, aad, pt)": Encrypt and authenticate plaintext "pt" with associated data "aad" using symmetric key "key" and nonce "nonce", yielding ciphertext and tag "ct". This function can raise a "MessageLimitReachedError" upon failure. - "Open(key, nonce, aad, ct)": Decrypt ciphertext and tag "ct" using associated data "aad" with symmetric key "key" and nonce "nonce", returning plaintext message "pt". This function can raise an "OpenError" or "MessageLimitReachedError" upon failure. - "Nk": The length in bytes of a key for this algorithm. - "Nn": The length in bytes of a nonce for this algorithm. Beyond the above, a KEM MAY also expose the following functions, whose behavior is detailed in Section 7.1.2: * "SerializePrivateKey(skX)": Produce a byte string of length "Nsk" encoding the private key "skX". * "DeserializePrivateKey(skXm)": Parse a byte string of length "Nsk" to recover a private key. This function can raise a "DeserializeError" error upon "skXm" deserialization failure. A _ciphersuite_ is a triple (KEM, KDF, AEAD) containing a choice of algorithm for each primitive. A set of algorithm identifiers for concrete instantiations of these primitives is provided in Section 7. Algorithm identifier values are two bytes long. Barnes, et al. Expires 27 November 2021 [Page 7] Internet-Draft HPKE May 2021 Note that "GenerateKeyPair" can be implemented as "DeriveKeyPair(random(Nsk))". The notation "pk(skX)", depending on its use and the KEM and its implementation, is either the computation of the public key using the private key, or just syntax expressing the retrieval of the public key assuming it is stored along with the private key object. The following two functions are defined to facilitate domain separation of KDF calls as well as context binding: def LabeledExtract(salt, label, ikm): labeled_ikm = concat("HPKE-v1", suite_id, label, ikm) return Extract(salt, labeled_ikm) def LabeledExpand(prk, label, info, L): labeled_info = concat(I2OSP(L, 2), "HPKE-v1", suite_id, label, info) return Expand(prk, labeled_info, L) The value of "suite_id" depends on where the KDF is used; it is assumed implicit from the implementation and not passed as a parameter. If used inside a KEM algorithm, "suite_id" MUST start with "KEM" and identify this KEM algorithm; if used in the remainder of HPKE, it MUST start with "HPKE" and identify the entire ciphersuite in use. See sections Section 4.1 and Section 5.1 for details. 4.1. DH-Based KEM Suppose we are given a KDF, and a Diffie-Hellman group providing the following operations: * "DH(skX, pkY)": Perform a non-interactive Diffie-Hellman exchange using the private key "skX" and public key "pkY" to produce a Diffie-Hellman shared secret of length "Ndh". This function can raise a "ValidationError" as described in Section 7.1.4. * "Ndh": The length in bytes of a Diffie-Hellman shared secret produced by "DH()". * "Nsk": The length in bytes of a Diffie-Hellman private key. Then we can construct a KEM that implements the interface defined in Section 4 called "DHKEM(Group, KDF)" in the following way, where "Group" denotes the Diffie-Hellman group and "KDF" the KDF. The function parameters "pkR" and "pkS" are deserialized public keys, and "enc" is a serialized public key. Since encapsulated keys are Barnes, et al. Expires 27 November 2021 [Page 8] Internet-Draft HPKE May 2021 Diffie-Hellman public keys in this KEM algorithm, we use "SerializePublicKey()" and "DeserializePublicKey()" to encode and decode them, respectively. "Npk" equals "Nenc". "GenerateKeyPair()" produces a key pair for the Diffie-Hellman group in use. Section 7.1.3 contains the "DeriveKeyPair()" function specification for DHKEMs defined in this document. def ExtractAndExpand(dh, kem_context): eae_prk = LabeledExtract("", "eae_prk", dh) shared_secret = LabeledExpand(eae_prk, "shared_secret", kem_context, Nsecret) return shared_secret def Encap(pkR): skE, pkE = GenerateKeyPair() dh = DH(skE, pkR) enc = SerializePublicKey(pkE) pkRm = SerializePublicKey(pkR) kem_context = concat(enc, pkRm) shared_secret = ExtractAndExpand(dh, kem_context) return shared_secret, enc def Decap(enc, skR): pkE = DeserializePublicKey(enc) dh = DH(skR, pkE) pkRm = SerializePublicKey(pk(skR)) kem_context = concat(enc, pkRm) shared_secret = ExtractAndExpand(dh, kem_context) return shared_secret def AuthEncap(pkR, skS): skE, pkE = GenerateKeyPair() dh = concat(DH(skE, pkR), DH(skS, pkR)) enc = SerializePublicKey(pkE) pkRm = SerializePublicKey(pkR) pkSm = SerializePublicKey(pk(skS)) kem_context = concat(enc, pkRm, pkSm) shared_secret = ExtractAndExpand(dh, kem_context) return shared_secret, enc def AuthDecap(enc, skR, pkS): pkE = DeserializePublicKey(enc) Barnes, et al. Expires 27 November 2021 [Page 9] Internet-Draft HPKE May 2021 dh = concat(DH(skR, pkE), DH(skR, pkS)) pkRm = SerializePublicKey(pk(skR)) pkSm = SerializePublicKey(pkS) kem_context = concat(enc, pkRm, pkSm) shared_secret = ExtractAndExpand(dh, kem_context) return shared_secret The implicit "suite_id" value used within "LabeledExtract" and "LabeledExpand" is defined as follows, where "kem_id" is defined in Section 7.1: suite_id = concat("KEM", I2OSP(kem_id, 2)) The KDF used in DHKEM can be equal to or different from the KDF used in the remainder of HPKE, depending on the chosen variant. Implementations MUST make sure to use the constants ("Nh") and function calls ("LabeledExtract", "LabeledExpand") of the appropriate KDF when implementing DHKEM. See Section 9.3 for a comment on the choice of a KDF for the remainder of HPKE, and Section 9.5 for the rationale of the labels. For the variants of DHKEM defined in this document, the size "Nsecret" of the KEM shared secret is equal to the output length of the hash function underlying the KDF. For P-256, P-384 and P-521, the size "Ndh" of the Diffie-Hellman shared secret is equal to 32, 48, and 66, respectively, corresponding to the x-coordinate of the resulting elliptic curve point [IEEE1363]. For X25519 and X448, the size "Ndh" of is equal to 32 and 56, respectively (see [RFC7748], Section 5). It is important to note that the "AuthEncap()" and "AuthDecap()" functions of the DHKEM variants defined in this document are vulnerable to key-compromise impersonation (KCI). This means the assurance that the KEM shared secret was generated by the holder of the private key "skS" does not hold if the recipient private key "skR" is compromised. See Section 9.1 for more details. Senders and recipients MUST validate KEM inputs and outputs as described in Section 7.1. Barnes, et al. Expires 27 November 2021 [Page 10] Internet-Draft HPKE May 2021 5. Hybrid Public Key Encryption In this section, we define a few HPKE variants. All variants take a recipient public key and a sequence of plaintexts "pt", and produce an encapsulated key "enc" and a sequence of ciphertexts "ct". These outputs are constructed so that only the holder of "skR" can decapsulate the key from "enc" and decrypt the ciphertexts. All the algorithms also take an "info" parameter that can be used to influence the generation of keys (e.g., to fold in identity information) and an "aad" parameter that provides Additional Authenticated Data to the AEAD algorithm in use. In addition to the base case of encrypting to a public key, we include three authenticated variants, one which authenticates possession of a pre-shared key, one which authenticates possession of a KEM private key, and one which authenticates possession of both a pre-shared key and a KEM private key. All authenticated variants contribute additional keying material to the encryption operation. The following one-byte values will be used to distinguish between modes: +===============+=======+ | Mode | Value | +===============+=======+ | mode_base | 0x00 | +---------------+-------+ | mode_psk | 0x01 | +---------------+-------+ | mode_auth | 0x02 | +---------------+-------+ | mode_auth_psk | 0x03 | +---------------+-------+ Table 1: HPKE Modes All these cases follow the same basic two-step pattern: 1. Set up an encryption context that is shared between the sender and the recipient. 2. Use that context to encrypt or decrypt content. A _context_ encodes the AEAD algorithm and key in use, and manages the nonces used so that the same nonce is not used with multiple plaintexts. It also has an interface for exporting secret values, as described in Section 5.3. See Section 5.2 for a description of this structure and its interfaces. HPKE decryption fails when the underlying AEAD decryption fails. Barnes, et al. Expires 27 November 2021 [Page 11] Internet-Draft HPKE May 2021 The constructions described here presume that the relevant non- private parameters ("enc", "psk_id", etc.) are transported between the sender and the recipient by some application making use of HPKE. Moreover, a recipient with more than one public key needs some way of determining which of its public keys was used for the encapsulation operation. As an example, applications may send this information alongside a ciphertext from sender to recipient. Specification of such a mechanism is left to the application. See Section 10 for more details. Note that some KEMs may not support "AuthEncap()" or "AuthDecap()". For such KEMs, only "mode_base" or "mode_psk" are supported. Future specifications which define new KEMs MUST indicate whether these modes are supported. See Section 7.1.6 for more details. The procedures described in this session are laid out in a Python- like pseudocode. The algorithms in use are left implicit. 5.1. Creating the Encryption Context The variants of HPKE defined in this document share a common key schedule that translates the protocol inputs into an encryption context. The key schedule inputs are as follows: * "mode" - A one-byte value indicating the HPKE mode, defined in Table 1. * "shared_secret" - A KEM shared secret generated for this transaction. * "info" - Application-supplied information (optional; default value ""). * "psk" - A pre-shared key (PSK) held by both the sender and the recipient (optional; default value ""). * "psk_id" - An identifier for the PSK (optional; default value ""). Senders and recipients MUST validate KEM inputs and outputs as described in Section 7.1. The "psk" and "psk_id" fields MUST appear together or not at all. That is, if a non-default value is provided for one of them, then the other MUST be set to a non-default value. This requirement is encoded in "VerifyPSKInputs()" below. Barnes, et al. Expires 27 November 2021 [Page 12] Internet-Draft HPKE May 2021 The "psk", "psk_id", and "info" fields have maximum lengths that depend on the KDF itself, on the definition of "LabeledExtract()", and on the constant labels used together with them. See Section 7.2.1 for precise limits on these lengths. The "key", "base_nonce", and "exporter_secret" computed by the key schedule have the property that they are only known to the holder of the recipient private key, and the entity that used the KEM to generate "shared_secret" and "enc". In the Auth and AuthPSK modes, the recipient is assured that the sender held the private key "skS". This assurance is limited for the DHKEM variants defined in this document because of key-compromise impersonation, as described in Section 4.1 and Section 9.1. If in the PSK and AuthPSK modes, the "psk" and "psk_id" arguments are provided as required, then the recipient is assured that the sender held the corresponding pre-shared key. See Section 9.1 for more details. The HPKE algorithm identifiers, i.e., the KEM "kem_id", KDF "kdf_id", and AEAD "aead_id" 2-byte code points as defined in Table 2, Table 3, and Table 5, respectively, are assumed implicit from the implementation and not passed as parameters. The implicit "suite_id" value used within "LabeledExtract" and "LabeledExpand" is defined based on them as follows: suite_id = concat( "HPKE", I2OSP(kem_id, 2), I2OSP(kdf_id, 2), I2OSP(aead_id, 2) ) Barnes, et al. Expires 27 November 2021 [Page 13] Internet-Draft HPKE May 2021 default_psk = "" default_psk_id = "" def VerifyPSKInputs(mode, psk, psk_id): got_psk = (psk != default_psk) got_psk_id = (psk_id != default_psk_id) if got_psk != got_psk_id: raise Exception("Inconsistent PSK inputs") if got_psk and (mode in [mode_base, mode_auth]): raise Exception("PSK input provided when not needed") if (not got_psk) and (mode in [mode_psk, mode_auth_psk]): raise Exception("Missing required PSK input") def KeySchedule(mode, shared_secret, info, psk, psk_id): VerifyPSKInputs(mode, psk, psk_id) psk_id_hash = LabeledExtract("", "psk_id_hash", psk_id) info_hash = LabeledExtract("", "info_hash", info) key_schedule_context = concat(mode, psk_id_hash, info_hash) secret = LabeledExtract(shared_secret, "secret", psk) key = LabeledExpand(secret, "key", key_schedule_context, Nk) base_nonce = LabeledExpand(secret, "base_nonce", key_schedule_context, Nn) exporter_secret = LabeledExpand(secret, "exp", key_schedule_context, Nh) return Context(key, base_nonce, 0, exporter_secret) The "ROLE" template parameter is either S or R, depending on the role of sender or recipient, respectively. See Section 5.2 for a discussion of the key schedule output, including the role-specific "Context" structure and its API. Note that the "key_schedule_context" construction in "KeySchedule()" is equivalent to serializing a structure of the following form in the TLS presentation syntax: struct { uint8 mode; opaque psk_id_hash[Nh]; opaque info_hash[Nh]; } KeyScheduleContext; Barnes, et al. Expires 27 November 2021 [Page 14] Internet-Draft HPKE May 2021 5.1.1. Encryption to a Public Key The most basic function of an HPKE scheme is to enable encryption to the holder of a given KEM private key. The "SetupBaseS()" and "SetupBaseR()" procedures establish contexts that can be used to encrypt and decrypt, respectively, for a given private key. The KEM shared secret is combined via the KDF with information describing the key exchange, as well as the explicit "info" parameter provided by the caller. The parameter "pkR" is a public key, and "enc" is an encapsulated KEM shared secret. def SetupBaseS(pkR, info): shared_secret, enc = Encap(pkR) return enc, KeyScheduleS(mode_base, shared_secret, info, default_psk, default_psk_id) def SetupBaseR(enc, skR, info): shared_secret = Decap(enc, skR) return KeyScheduleR(mode_base, shared_secret, info, default_psk, default_psk_id) 5.1.2. Authentication using a Pre-Shared Key This variant extends the base mechanism by allowing the recipient to authenticate that the sender possessed a given PSK. The PSK also improves confidentiality guarantees in certain adversary models, as described in more detail in Section 9.1. We assume that both parties have been provisioned with both the PSK value "psk" and another byte string "psk_id" that is used to identify which PSK should be used. The primary difference from the base case is that the "psk" and "psk_id" values are used as "ikm" inputs to the KDF (instead of using the empty string). The PSK MUST have at least 32 bytes of entropy and SHOULD be of length "Nh" bytes or longer. See Section 9.4 for a more detailed discussion. def SetupPSKS(pkR, info, psk, psk_id): shared_secret, enc = Encap(pkR) return enc, KeyScheduleS(mode_psk, shared_secret, info, psk, psk_id) def SetupPSKR(enc, skR, info, psk, psk_id): shared_secret = Decap(enc, skR) return KeyScheduleR(mode_psk, shared_secret, info, psk, psk_id) Barnes, et al. Expires 27 November 2021 [Page 15] Internet-Draft HPKE May 2021 5.1.3. Authentication using an Asymmetric Key This variant extends the base mechanism by allowing the recipient to authenticate that the sender possessed a given KEM private key. This assurance is based on the assumption that "AuthDecap(enc, skR, pkS)" produces the correct KEM shared secret only if the encapsulated value "enc" was produced by "AuthEncap(pkR, skS)", where "skS" is the private key corresponding to "pkS". In other words, at most two entities (precisely two, in the case of DHKEM) could have produced this secret, so if the recipient is at most one, then the sender is the other with overwhelming probability. The primary difference from the base case is that the calls to "Encap()" and "Decap()" are replaced with calls to "AuthEncap()" and "AuthDecap()", which add the sender public key to their internal context string. The function parameters "pkR" and "pkS" are public keys, and "enc" is an encapsulated KEM shared secret. Obviously, this variant can only be used with a KEM that provides "AuthEncap()" and "AuthDecap()" procedures. This mechanism authenticates only the key pair of the sender, not any other identifier. If an application wishes to bind HPKE ciphertexts or exported secrets to another identity for the sender (e.g., an email address or domain name), then this identifier should be included in the "info" parameter to avoid identity mis-binding issues [IMB]. def SetupAuthS(pkR, info, skS): shared_secret, enc = AuthEncap(pkR, skS) return enc, KeyScheduleS(mode_auth, shared_secret, info, default_psk, default_psk_id) def SetupAuthR(enc, skR, info, pkS): shared_secret = AuthDecap(enc, skR, pkS) return KeyScheduleR(mode_auth, shared_secret, info, default_psk, default_psk_id) 5.1.4. Authentication using both a PSK and an Asymmetric Key This mode is a straightforward combination of the PSK and authenticated modes. The PSK is passed through to the key schedule as in the former, and as in the latter, we use the authenticated KEM variants. Barnes, et al. Expires 27 November 2021 [Page 16] Internet-Draft HPKE May 2021 def SetupAuthPSKS(pkR, info, psk, psk_id, skS): shared_secret, enc = AuthEncap(pkR, skS) return enc, KeyScheduleS(mode_auth_psk, shared_secret, info, psk, psk_id) def SetupAuthPSKR(enc, skR, info, psk, psk_id, pkS): shared_secret = AuthDecap(enc, skR, pkS) return KeyScheduleR(mode_auth_psk, shared_secret, info, psk, psk_id) The PSK MUST have at least 32 bytes of entropy and SHOULD be of length "Nh" bytes or longer. See Section 9.4 for a more detailed discussion. 5.2. Encryption and Decryption HPKE allows multiple encryption operations to be done based on a given setup transaction. Since the public-key operations involved in setup are typically more expensive than symmetric encryption or decryption, this allows applications to amortize the cost of the public-key operations, reducing the overall overhead. In order to avoid nonce reuse, however, this encryption must be stateful. Each of the setup procedures above produces a role- specific context object that stores the AEAD and Secret Export parameters. The AEAD parameters consist of: * The AEAD algorithm in use * A secret "key" * A base nonce "base_nonce" * A sequence number (initially 0) The Secret Export parameters consist of: * The HPKE ciphersuite in use * An "exporter_secret" used for the Secret Export interface; see Section 5.3 Barnes, et al. Expires 27 November 2021 [Page 17] Internet-Draft HPKE May 2021 All these parameters except the AEAD sequence number are constant. The sequence number provides nonce uniqueness: The nonce used for each encryption or decryption operation is the result of XORing "base_nonce" with the current sequence number, encoded as a big- endian integer of the same length as "base_nonce". Implementations MAY use a sequence number that is shorter than the nonce length (padding on the left with zero), but MUST raise an error if the sequence number overflows. Encryption is unidirectional from sender to recipient. The sender's context can encrypt a plaintext "pt" with associated data "aad" as follows: def ContextS.Seal(aad, pt): ct = Seal(self.key, self.ComputeNonce(self.seq), aad, pt) self.IncrementSeq() return ct The recipient's context can decrypt a ciphertext "ct" with associated data "aad" as follows: def ContextR.Open(aad, ct): pt = Open(self.key, self.ComputeNonce(self.seq), aad, ct) if pt == OpenError: raise OpenError self.IncrementSeq() return pt Each encryption or decryption operation increments the sequence number for the context in use. The per-message nonce and sequence number increment details are as follows: def Context.ComputeNonce(seq): seq_bytes = I2OSP(seq, Nn) return xor(self.base_nonce, seq_bytes) def Context.IncrementSeq(): if self.seq >= (1 << (8*Nn)) - 1: raise MessageLimitReachedError self.seq += 1 The sender's context MUST NOT be used for decryption. Similarly, the recipient's context MUST NOT be used for encryption. Higher-level protocols re-using the HPKE key exchange for more general purposes can derive separate keying material as needed using use the Secret Export interface; see Section 5.3 and Section 9.7 for more details. Barnes, et al. Expires 27 November 2021 [Page 18] Internet-Draft HPKE May 2021 It is up to the application to ensure that encryptions and decryptions are done in the proper sequence, so that encryption and decryption nonces align. If "ContextS.Seal()" or "ContextR.Open()" would cause the "seq" field to overflow, then the implementation MUST fail with an error. (In the pseudocode below, "Context.IncrementSeq()" fails with an error when "seq" overflows, which causes "ContextS.Seal()" and "ContextR.Open()" to fail accordingly.) Note that the internal "Seal()" and "Open()" calls inside correspond to the context's AEAD algorithm. 5.3. Secret Export HPKE provides an interface for exporting secrets from the encryption context using a variable-length PRF, similar to the TLS 1.3 exporter interface (see [RFC8446], Section 7.5). This interface takes as input a context string "exporter_context" and a desired length "L" in bytes, and produces a secret derived from the internal exporter secret using the corresponding KDF Expand function. For the KDFs defined in this specification, "L" has a maximum value of "255*Nh". Future specifications which define new KDFs MUST specify a bound for "L". The "exporter_context" field has a maximum length that depends on the KDF itself, on the definition of "LabeledExpand()", and on the constant labels used together with them. See Section 7.2.1 for precise limits on this length. def Context.Export(exporter_context, L): return LabeledExpand(self.exporter_secret, "sec", exporter_context, L) Applications that do not use the encryption API in Section 5.2 can use the export-only AEAD ID "0xFFFF" when computing the key schedule. Such applications can avoid computing the "key" and "base_nonce" values in the key schedule, as they are not used by the Export interface described above. 6. Single-Shot APIs 6.1. Encryption and Decryption In many cases, applications encrypt only a single message to a recipient's public key. This section provides templates for HPKE APIs that implement stateless "single-shot" encryption and decryption using APIs specified in Section 5.1.1 and Section 5.2: Barnes, et al. Expires 27 November 2021 [Page 19] Internet-Draft HPKE May 2021 def Seal(pkR, info, aad, pt, ...): enc, ctx = SetupS(pkR, info, ...) ct = ctx.Seal(aad, pt) return enc, ct def Open(enc, skR, info, aad, ct, ...): ctx = SetupR(enc, skR, info, ...) return ctx.Open(aad, ct) The "MODE" template parameter is one of Base, PSK, Auth, or AuthPSK. The optional parameters indicated by "..." depend on "MODE" and may be empty. "SetupBase()", for example, has no additional parameters. "SealAuthPSK()" and "OpenAuthPSK()" would be implemented as follows: def SealAuthPSK(pkR, info, aad, pt, psk, psk_id, skS): enc, ctx = SetupAuthPSKS(pkR, info, psk, psk_id, skS) ct = ctx.Seal(aad, pt) return enc, ct def OpenAuthPSK(enc, skR, info, aad, ct, psk, psk_id, pkS): ctx = SetupAuthPSKR(enc, skR, info, psk, psk_id, pkS) return ctx.Open(aad, ct) 6.2. Secret Export Applications may also want to derive a secret known only to a given recipient. This section provides templates for HPKE APIs that implement stateless "single-shot" secret export using APIs specified in Section 5.3: def SendExport(pkR, info, exporter_context, L, ...): enc, ctx = SetupS(pkR, info, ...) exported = ctx.Export(exporter_context, L) return enc, exported def ReceiveExport(enc, skR, info, exporter_context, L, ...): ctx = SetupR(enc, skR, info, ...) return ctx.Export(exporter_context, L) As in Section 6.1, the "MODE" template parameter is one of Base, PSK, Auth, or AuthPSK. The optional parameters indicated by "..." depend on "MODE" and may be empty. 7. Algorithm Identifiers Barnes, et al. Expires 27 November 2021 [Page 20] Internet-Draft HPKE May 2021 7.1. Key Encapsulation Mechanisms (KEMs) +=======+===============+=========+====+===+===+====+===============+ |Value | KEM | Nsecret |Nenc|Npk|Nsk|Auth| Reference | +=======+===============+=========+====+===+===+====+===============+ |0x0000 | (reserved) | N/A |N/A |N/A|N/A|yes | N/A | +-------+---------------+---------+----+---+---+----+---------------+ |0x0010 | DHKEM(P-256, | 32 |65 |65 |32 |yes | [NISTCurves], | | | HKDF-SHA256) | | | | | | [RFC5869] | +-------+---------------+---------+----+---+---+----+---------------+ |0x0011 | DHKEM(P-384, | 48 |97 |97 |48 |yes | [NISTCurves], | | | HKDF-SHA384) | | | | | | [RFC5869] | +-------+---------------+---------+----+---+---+----+---------------+ |0x0012 | DHKEM(P-521, | 64 |133 |133|66 |yes | [NISTCurves], | | | HKDF-SHA512) | | | | | | [RFC5869] | +-------+---------------+---------+----+---+---+----+---------------+ |0x0020 | DHKEM(X25519, | 32 |32 |32 |32 |yes | [RFC7748], | | | HKDF-SHA256) | | | | | | [RFC5869] | +-------+---------------+---------+----+---+---+----+---------------+ |0x0021 | DHKEM(X448, | 64 |56 |56 |56 |yes | [RFC7748], | | | HKDF-SHA512) | | | | | | [RFC5869] | +-------+---------------+---------+----+---+---+----+---------------+ Table 2: KEM IDs The "Auth" column indicates if the KEM algorithm provides the "AuthEncap()"/"AuthDecap()" interface. The meaning of all other columns is explained in Section 11.1. 7.1.1. SerializePublicKey and DeserializePublicKey For P-256, P-384 and P-521, the "SerializePublicKey()" function of the KEM performs the uncompressed Elliptic-Curve-Point-to-Octet- String conversion according to [SECG]. "DeserializePublicKey()" performs the uncompressed Octet-String-to-Elliptic-Curve-Point conversion. For X25519 and X448, the "SerializePublicKey()" and "DeserializePublicKey()" functions are the identity function, since these curves already use fixed-length byte strings for public keys. Some deserialized public keys MUST be validated before they can be used. See Section 7.1.4 for specifics. Barnes, et al. Expires 27 November 2021 [Page 21] Internet-Draft HPKE May 2021 7.1.2. SerializePrivateKey and DeserializePrivateKey As per [SECG], P-256, P-384, and P-521 private keys are field elements in the scalar field of the curve being used. For this section, and for Section 7.1.3, it is assumed that implementers of ECDH over these curves use an integer representation of private keys that is compatible with the "OS2IP()" function. For P-256, P-384 and P-521, the "SerializePrivateKey()" function of the KEM performs the Field-Element-to-Octet-String conversion according to [SECG]. If the private key is an integer outside the range "[0, order-1]", where "order" is the order of the curve being used, the private key MUST be reduced to its representative in "[0, order-1]" before being serialized. "DeserializePrivateKey()" performs the Octet-String-to-Field-Element conversion according to [SECG]. For X25519 and X448, private keys are identical to their byte string representation, so little processing has to be done. The "SerializePrivateKey()" function MUST clamp its output and "DeserializePrivateKey()" MUST clamp its input, where _clamping_ refers to the bitwise operations performed on "k" in the "decodeScalar25519()" and "decodeScalar448()" functions defined in section 5 of [RFC7748]. To catch invalid keys early on, implementers of DHKEMs SHOULD check that deserialized private keys are not equivalent to 0 (mod "order"), where "order" is the order of the DH group. Note that this property is trivially true for X25519 and X448 groups, since clamped values can never be 0 (mod "order"). 7.1.3. DeriveKeyPair The keys that "DeriveKeyPair()" produces have only as much entropy as the provided input keying material. For a given KEM, the "ikm" parameter given to "DeriveKeyPair()" SHOULD have length at least "Nsk", and SHOULD have at least "Nsk" bytes of entropy. All invocations of KDF functions (such as "LabeledExtract" or "LabeledExpand") in any DHKEM's "DeriveKeyPair()" function use the DHKEM's associated KDF (as opposed to the ciphersuite's KDF). For P-256, P-384 and P-521, the "DeriveKeyPair()" function of the KEM performs rejection sampling over field elements: Barnes, et al. Expires 27 November 2021 [Page 22] Internet-Draft HPKE May 2021 def DeriveKeyPair(ikm): dkp_prk = LabeledExtract("", "dkp_prk", ikm) sk = 0 counter = 0 while sk == 0 or sk >= order: if counter > 255: raise DeriveKeyPairError bytes = LabeledExpand(dkp_prk, "candidate", I2OSP(counter, 1), Nsk) bytes[0] = bytes[0] & bitmask sk = OS2IP(bytes) counter = counter + 1 return (sk, pk(sk)) "order" is the order of the curve being used (see section D.1.2 of [NISTCurves]), and is listed below for completeness. P-256: 0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551 P-384: 0xffffffffffffffffffffffffffffffffffffffffffffffffc7634d81f4372ddf 581a0db248b0a77aecec196accc52973 P-521: 0x01ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff fa51868783bf2f966b7fcc0148f709a5d03bb5c9b8899c47aebb6fb71e91386409 "bitmask" is defined to be 0xFF for P-256 and P-384, and 0x01 for P-521. The precise likelihood of "DeriveKeyPair()" failing with DeriveKeyPairError depends on the group being used, but it is negligibly small in all cases. For X25519 and X448, the "DeriveKeyPair()" function applies a KDF to the input: def DeriveKeyPair(ikm): dkp_prk = LabeledExtract("", "dkp_prk", ikm) sk = LabeledExpand(dkp_prk, "sk", "", Nsk) return (sk, pk(sk)) Barnes, et al. Expires 27 November 2021 [Page 23] Internet-Draft HPKE May 2021 7.1.4. Validation of Inputs and Outputs The following public keys are subject to validation if the group requires public key validation: the sender MUST validate the recipient's public key "pkR"; the recipient MUST validate the ephemeral public key "pkE"; in authenticated modes, the recipient MUST validate the sender's static public key "pkS". Validation failure yields a "ValidationError". For P-256, P-384 and P-521, senders and recipients MUST perform partial public-key validation on all public key inputs, as defined in section 5.6.2.3.4 of [keyagreement]. This includes checking that the coordinates are in the correct range, that the point is on the curve, and that the point is not the point at infinity. Additionally, senders and recipients MUST ensure the Diffie-Hellman shared secret is not the point at infinity. For X25519 and X448, public keys and Diffie-Hellman outputs MUST be validated as described in [RFC7748]. In particular, recipients MUST check whether the Diffie-Hellman shared secret is the all-zero value and abort if so. 7.1.5. KEM Key Reuse An "ikm" input to "DeriveKeyPair()" (Section 7.1.3) MUST NOT be reused elsewhere, in particular not with "DeriveKeyPair()" of a different KEM. The randomness used in "Encap()" and "AuthEncap()" to generate the KEM shared secret or its encapsulation MUST NOT be reused elsewhere. As a sender or recipient KEM key pair works with all modes, it can be used with multiple modes in parallel. HPKE is constructed to be secure in such settings due to domain separation using the "suite_id" variable. However, there is no formal proof of security at the time of writing; [HPKEAnalysis] and [ABHKLR20] only analyze isolated modes. 7.1.6. Future KEMs Section 9.2 lists security requirements on a KEM used within HPKE. The "AuthEncap()" and "AuthDecap()" functions are OPTIONAL. If a KEM algorithm does not provide them, only the Base and PSK modes of HPKE are supported. Future specifications which define new KEMs MUST indicate whether or not Auth and AuthPSK modes are supported. Barnes, et al. Expires 27 November 2021 [Page 24] Internet-Draft HPKE May 2021 A KEM algorithm may support different encoding algorithms, with different output lengths, for KEM public keys. Such KEM algorithms MUST specify only one encoding algorithm whose output length is "Npk". 7.2. Key Derivation Functions (KDFs) +========+=============+=====+===========+ | Value | KDF | Nh | Reference | +========+=============+=====+===========+ | 0x0000 | (reserved) | N/A | N/A | +--------+-------------+-----+-----------+ | 0x0001 | HKDF-SHA256 | 32 | [RFC5869] | +--------+-------------+-----+-----------+ | 0x0002 | HKDF-SHA384 | 48 | [RFC5869] | +--------+-------------+-----+-----------+ | 0x0003 | HKDF-SHA512 | 64 | [RFC5869] | +--------+-------------+-----+-----------+ Table 3: KDF IDs 7.2.1. Input Length Restrictions This document defines "LabeledExtract()" and "LabeledExpand()" based on the KDFs listed above. These functions add prefixes to their respective inputs "ikm" and "info" before calling the KDF's "Extract()" and "Expand()" functions. This leads to a reduction of the maximum input length that is available for the inputs "psk", "psk_id", "info", "exporter_context", "ikm", i.e., the variable- length parameters provided by HPKE applications. The following table lists the maximum allowed lengths of these fields for the KDFs defined in this document, as inclusive bounds in bytes: Barnes, et al. Expires 27 November 2021 [Page 25] Internet-Draft HPKE May 2021 +==================+==============+===============+===============+ | Input | HKDF-SHA256 | HKDF-SHA384 | HKDF-SHA512 | +==================+==============+===============+===============+ | psk | 2^{61} - 88 | 2^{125} - 152 | 2^{125} - 152 | +------------------+--------------+---------------+---------------+ | psk_id | 2^{61} - 93 | 2^{125} - 157 | 2^{125} - 157 | +------------------+--------------+---------------+---------------+ | info | 2^{61} - 91 | 2^{125} - 155 | 2^{125} - 155 | +------------------+--------------+---------------+---------------+ | exporter_context | 2^{61} - 120 | 2^{125} - 200 | 2^{125} - 216 | +------------------+--------------+---------------+---------------+ | ikm | 2^{61} - 84 | 2^{125} - 148 | 2^{125} - 148 | | (DeriveKeyPair) | | | | +------------------+--------------+---------------+---------------+ Table 4: Application Input Limits This shows that the limits are only marginally smaller than the maximum input length of the underlying hash function; these limits are large and unlikely to be reached in practical applications. Future specifications which define new KDFs MUST specify bounds for these variable-length parameters. The RECOMMENDED limit for these values is 64 bytes. This would enable interoperability with implementations that statically allocate memory for these inputs to avoid memory allocations. The values for "psk", "psk_id", "info", and "ikm" which are inputs to "LabeledExtract()" were computed with the following expression: max_size_hash_input - Nb - size_version_label - size_suite_id - size_input_label The value for "exporter_context" which is an input to "LabeledExpand()" was computed with the following expression: max_size_hash_input - Nb - Nh - size_version_label - size_suite_id - size_input_label - 2 - 1 Barnes, et al. Expires 27 November 2021 [Page 26] Internet-Draft HPKE May 2021 In these equations, "max_size_hash_input" is the maximum input length of the underlying hash function in bytes, "Nb" is the block size of the underlying hash function in bytes, "size_version_label" is the size of "HPKE-v1" in bytes and equals 7, "size_suite_id" is the size of the "suite_id" in bytes and equals 5 for DHKEM (relevant for "ikm") and 10 for the remainder of HPKE (relevant for "psk", "psk_id", "info", "exporter_context"), and "size_input_label" is the size in bytes of the label used as parameter to "LabeledExtract()" or "LabeledExpand()", the maximum of which is 13 across all labels in this document. 7.3. Authenticated Encryption with Associated Data (AEAD) Functions +========+==================+=====+=====+=============+ | Value | AEAD | Nk | Nn | Reference | +========+==================+=====+=====+=============+ | 0x0000 | (reserved) | N/A | N/A | N/A | +--------+------------------+-----+-----+-------------+ | 0x0001 | AES-128-GCM | 16 | 12 | [GCM] | +--------+------------------+-----+-----+-------------+ | 0x0002 | AES-256-GCM | 32 | 12 | [GCM] | +--------+------------------+-----+-----+-------------+ | 0x0003 | ChaCha20Poly1305 | 32 | 12 | [RFC8439] | +--------+------------------+-----+-----+-------------+ | 0xFFFF | Export-only | N/A | N/A | [[RFCXXXX]] | +--------+------------------+-----+-----+-------------+ Table 5: AEAD IDs The "0xFFFF" AEAD ID is reserved for applications which only use the Export interface; see Section 5.3 for more details. 8. API Considerations The high-level HPKE APIs specified in this document are all fallible. For example, "Decap()" can fail if the encapsulated key "enc" is invalid, and "Open()" may fail if ciphertext decryption fails. The explicit errors generated throughout this specification, along with the conditions that lead to each error, are as follows: * "ValidationError": KEM input or output validation failure; Section 4.1. * "DeserializeError": Public or private key deserialization failure; Section 4. * "DecapError": "Decap()" failure; Section 4. Barnes, et al. Expires 27 November 2021 [Page 27] Internet-Draft HPKE May 2021 * "OpenError": Context AEAD "Open()" failure; Section 4 and Section 5.2. * "MessageLimitReachedError": Context AEAD sequence number overflow; Section 4 and Section 5.2. * "DeriveKeyPairError": Key pair derivation failure; Section 7.1.3. Implicit errors may also occur. As an example, certain classes of failures, e.g., malformed recipient public keys, may not yield explicit errors. For example, for the DHKEM variant described in this specification, the "Encap()" algorithm fails when given an invalid recipient public key. However, other KEM algorithms may not have an efficient algorithm for verifying the validity of public keys. As a result, an equivalent error may not manifest until AEAD decryption at the recipient. As another example, DHKEM's "AuthDecap()" function will produce invalid output if given the wrong sender public key. This error is not detectable until subsequent AEAD decryption. The errors in this document are meant as a guide to implementors. They are not an exhaustive list of all the errors an implementation might emit. For example, future KEMs might have internal failure cases, or an implementation might run out of memory. Applications using HPKE APIs should not assume that the errors here are complete, nor should they assume certain classes of errors will always manifest the same way for all ciphersuites. For example, the DHKEM specified in this document will emit a "DeserializationError" or "ValidationError" if a KEM public key is invalid. However, a new KEM might not have an efficient algorithm for determining whether or not a public key is valid. In this case, an invalid public key might instead yield an "OpenError" when trying to decrypt a ciphertext. 9. Security Considerations 9.1. Security Properties HPKE has several security goals, depending on the mode of operation, against active and adaptive attackers that can compromise partial secrets of senders and recipients. The desired security goals are detailed below: * Message secrecy: Confidentiality of the sender's messages against chosen ciphertext attacks Barnes, et al. Expires 27 November 2021 [Page 28] Internet-Draft HPKE May 2021 * Export key secrecy: Indistinguishability of each export secret from a uniformly random bitstring of equal length, i.e., "Context.Export" is a variable-length PRF * Sender authentication: Proof of sender origin for PSK, Auth, and AuthPSK modes These security goals are expected to hold for any honest sender and honest recipient keys, as well as if the honest sender and honest recipient keys are the same. As noted in Section 9.6.2, HPKE does not provide forward secrecy. In the Base and Auth modes, the secrecy properties are only expected to hold if the recipient private key "skR" is not compromised at any point in time. In the PSK and AuthPSK modes, the secrecy properties are expected to hold if the recipient private key "skR" and the pre- shared key are not both compromised at any point in time. In the Auth mode, sender authentication is generally expected to hold if the sender private key "skS" is not compromised at the time of message reception. In the AuthPSK mode, sender authentication is generally expected to hold if at the time of message reception, the sender private key skS and the pre-shared key are not both compromised. HPKE mitigates malleability problems (called benign malleability [SECG]) in prior public key encryption standards based on ECIES by including all public keys in the context key schedule. 9.1.1. Key-Compromise Impersonation The DHKEM variants defined in this document are vulnerable to key- compromise impersonation attacks [BJM97], which means that sender authentication cannot be expected to hold in the Auth mode if the recipient private key "skR" is compromised, and in the AuthPSK mode if the pre-shared key and the recipient private key "skR" are both compromised. NaCl's "box" interface [NaCl] has the same issue. At the same time, this enables repudiability. As shown by [ABHKLR20], key-compromise impersonation attacks are generally possible on HPKE because KEM ciphertexts are not bound to HPKE messages. An adversary who knows a recipient's private key can decapsulate an observed KEM ciphertext, compute the key schedule, and encrypt an arbitrary message that the recipient will accept as coming from the original sender. Importantly, this is possible even with a KEM that is resistant to key-compromise impersonation attacks. As a result, mitigating this issue requires fundamental changes that are out-of-scope of this specification. Barnes, et al. Expires 27 November 2021 [Page 29] Internet-Draft HPKE May 2021 Applications that require resistance against key-compromise impersonation SHOULD take extra steps to prevent this attack. One possibility is to produce a digital signature over "(enc, ct)" tuples using a sender's private key - where "ct" is an AEAD ciphertext produced by the single-shot or multi-shot API, and "enc" the corresponding KEM encapsulated key. Given these properties, pre-shared keys strengthen both the authentication and the secrecy properties in certain adversary models. One particular example in which this can be useful is a hybrid quantum setting: if a non-quantum-resistant KEM used with HPKE is broken by a quantum computer, the security properties are preserved through the use of a pre-shared key. This assumes that the pre-shared key has not been compromised, as described in [WireGuard]. 9.1.2. Computational Analysis It is shown in [CS01] that a hybrid public-key encryption scheme of essentially the same form as the Base mode described here is IND- CCA2-secure as long as the underlying KEM and AEAD schemes are IND- CCA2-secure. Moreover, it is shown in [HHK06] that IND-CCA2 security of the KEM and the data encapsulation mechanism are necessary conditions to achieve IND-CCA2 security for hybrid public-key encryption. The main difference between the scheme proposed in [CS01] and the Base mode in this document (both named HPKE) is that we interpose some KDF calls between the KEM and the AEAD. Analyzing the HPKE Base mode instantiation in this document therefore requires verifying that the additional KDF calls do not cause the IND-CCA2 property to fail, as well as verifying the additional export key secrecy property. Analysis of the PSK, Auth, and AuthPSK modes defined in this document additionally requires verifying the sender authentication property. While the PSK mode just adds supplementary keying material to the key schedule, the Auth and AuthPSK modes make use of a non-standard authenticated KEM construction. Generally, the authenticated modes of HPKE can be viewed and analyzed as flavors of signcryption [SigncryptionDZ10]. A preliminary computational analysis of all HPKE modes has been done in [HPKEAnalysis], indicating asymptotic security for the case where the KEM is DHKEM, the AEAD is any IND-CPA and INT-CTXT-secure scheme, and the DH group and KDF satisfy the following conditions: * DH group: The gap Diffie-Hellman (GDH) problem is hard in the appropriate subgroup [GAP]. Barnes, et al. Expires 27 November 2021 [Page 30] Internet-Draft HPKE May 2021 * "Extract()" and "Expand()" (in DHKEM): "Extract()" can be modeled as a random oracle. "Expand()" can be modeled as a pseudorandom function, wherein the first argument is the key. * "Extract()" and "Expand()" (elsewhere): "Extract()" can be modeled as a random oracle. "Expand()" can be modeled as a pseudorandom function, wherein the first argument is the key. In particular, the KDFs and DH groups defined in this document (see Section 7.2 and Section 7.1) satisfy these properties when used as specified. The analysis in [HPKEAnalysis] demonstrates that under these constraints, HPKE continues to provide IND-CCA2 security, and provides the additional properties noted above. Also, the analysis confirms the expected properties hold under the different key compromise cases mentioned above. The analysis considers a sender that sends one message using the encryption context, and additionally exports two independent secrets using the secret export interface. The table below summarizes the main results from [HPKEAnalysis]. N/A means that a property does not apply for the given mode, whereas "y" means the given mode satisfies the property. +=========+==============+=============+==============+ | Variant | Message Sec. | Export Sec. | Sender Auth. | +=========+==============+=============+==============+ | Base | y | y | N/A | +---------+--------------+-------------+--------------+ | PSK | y | y | y | +---------+--------------+-------------+--------------+ | Auth | y | y | y | +---------+--------------+-------------+--------------+ | AuthPSK | y | y | y | +---------+--------------+-------------+--------------+ Table 6 If non-DH-based KEMs are to be used with HPKE, further analysis will be necessary to prove their security. The results from [CS01] provide some indication that any IND-CCA2-secure KEM will suffice here, but are not conclusive given the differences in the schemes. A detailed computational analysis of HPKE's Auth mode single-shot encryption API has been done in [ABHKLR20]. The paper defines security notions for authenticated KEMs and for authenticated public key encryption, using the outsider and insider security terminology known from signcryption [SigncryptionDZ10]. The analysis proves that DHKEM's "AuthEncap()"/"AuthDecap()" interface fulfills these notions for all Diffie-Hellman groups specified in this document, and Barnes, et al. Expires 27 November 2021 [Page 31] Internet-Draft HPKE May 2021 indicates exact security bounds, under the assumption that the gap Diffie-Hellman (GDH) problem is hard in the appropriate subgroup [GAP], and that HKDF can be modeled as a random oracle. Further, [ABHKLR20] proves composition theorems, showing that HPKE's Auth mode fulfills the security notions of authenticated public key encryption for all KDFs and AEAD schemes specified in this document, given any authenticated KEM satisfying the previously defined security notions for authenticated KEMs. The theorems assume that the KEM is perfectly correct; they could easily be adapted to work with KEMs that have a non-zero but negligible probability for decryption failure. The assumptions on the KDF are that "Extract()" and "Expand()" can be modeled as pseudorandom functions wherein the first argument is the key, respectively. The assumption for the AEAD is IND-CPA and IND-CTXT security. In summary, the analysis in [ABHKLR20] proves that the single-shot encryption API of HPKE's Auth mode satisfies the desired message confidentiality and sender authentication properties listed at the beginning of this section; it does not consider multiple messages, nor the secret export API. 9.1.3. Post-Quantum Security All of [CS01], [HPKEAnalysis], and [ABHKLR20] are premised on classical security models and assumptions, and do not consider adversaries capable of quantum computation. A full proof of post- quantum security would need to take appropriate security models and assumptions into account, in addition to simply using a post-quantum KEM. However, the composition theorems from [ABHKLR20] for HPKE's Auth mode only make standard assumptions (i.e., no random oracle assumption) that are expected to hold against quantum adversaries (although with slightly worse bounds). Thus, these composition theorems, in combination with a post-quantum-secure authenticated KEM, guarantee the post-quantum security of HPKE's Auth mode. In future work, the analysis from [ABHKLR20] can be extended to cover HPKE's other modes and desired security properties. The hybrid quantum-resistance property described above, which is achieved by using the PSK or AuthPSK mode, is not proven in [HPKEAnalysis] because this analysis requires the random oracle model; in a quantum setting, this model needs adaption to, for example, the quantum random oracle model. Barnes, et al. Expires 27 November 2021 [Page 32] Internet-Draft HPKE May 2021 9.2. Security Requirements on a KEM used within HPKE A KEM used within HPKE MUST allow HPKE to satisfy its desired security properties described in Section 9.1. Section 9.5 lists requirements concerning domain separation. In particular, the KEM shared secret MUST be a uniformly random byte string of length "Nsecret". This means, for instance, that it would not be sufficient if the KEM shared secret is only uniformly random as an element of some set prior to its encoding as byte string. 9.2.1. Encap/Decap Interface As mentioned in Section 9, [CS01] provides some indications that if the KEM's "Encap()"/"Decap()" interface (which is used in the Base and PSK modes), is IND-CCA2-secure, HPKE is able to satisfy its desired security properties. An appropriate definition of IND- CCA2-security for KEMs can be found in [CS01] and [BHK09]. 9.2.2. AuthEncap/AuthDecap Interface The analysis of HPKE's Auth mode single-shot encryption API in [ABHKLR20] provides composition theorems that guarantee that HPKE's Auth mode achieves its desired security properties if the KEM's "AuthEncap()"/"AuthDecap()" interface satisfies multi-user Outsider- CCA, Outsider-Auth, and Insider-CCA security as defined in the same paper. Intuitively, Outsider-CCA security formalizes confidentiality, and Outsider-Auth security formalizes authentication of the KEM shared secret in case none of the sender or recipient private keys are compromised. Insider-CCA security formalizes confidentiality of the KEM shared secret in case the sender private key is known or chosen by the adversary. (If the recipient private key is known or chosen by the adversary, confidentiality is trivially broken, because then the adversary knows all secrets on the recipient's side). An Insider-Auth security notion would formalize authentication of the KEM shared secret in case the recipient private key is known or chosen by the adversary. (If the sender private key is known or chosen by the adversary, it can create KEM ciphertexts in the name of the sender). Because of the generic attack on an analogous Insider- Auth security notion of HPKE described in Section 9.1, a definition of Insider-Auth security for KEMs used within HPKE is not useful. Barnes, et al. Expires 27 November 2021 [Page 33] Internet-Draft HPKE May 2021 9.3. Security Requirements on a KDF The choice of the KDF for the remainder of HPKE SHOULD be made based on the security level provided by the KEM and, if applicable, by the PSK. The KDF SHOULD have at least have the security level of the KEM and SHOULD at least have the security level provided by the PSK. 9.4. Pre-Shared Key Recommendations In the PSK and AuthPSK modes, the PSK MUST have at least 32 bytes of entropy and SHOULD be of length "Nh" bytes or longer. Using a PSK longer than 32 bytes but shorter than "Nh" bytes is permitted. HPKE is specified to use HKDF as key derivation function. HKDF is not designed to slow down dictionary attacks, see [RFC5869]. Thus, HPKE's PSK mechanism is not suitable for use with a low-entropy password as the PSK: in scenarios in which the adversary knows the KEM shared secret "shared_secret" and has access to an oracle that allows to distinguish between a good and a wrong PSK, it can perform PSK-recovering attacks. This oracle can be the decryption operation on a captured HPKE ciphertext or any other recipient behavior which is observably different when using a wrong PSK. The adversary knows the KEM shared secret "shared_secret" if it knows all KEM private keys of one participant. In the PSK mode this is trivially the case if the adversary acts as sender. To recover a lower entropy PSK, an attacker in this scenario can trivially perform a dictionary attack. Given a set "S" of possible PSK values, the attacker generates an HPKE ciphertext for each value in "S", and submits the resulting ciphertexts to the oracle to learn which PSK is being used by the recipient. Further, because HPKE uses AEAD schemes that are not key-committing, an attacker can mount a partitioning oracle attack [LGR20] which can recover the PSK from a set of "S" possible PSK values, with |S| = m*k, in roughly m + log k queries to the oracle using ciphertexts of length proportional to k, the maximum message length in blocks. The PSK must therefore be chosen with sufficient entropy so that m + log k is prohibitive for attackers (e.g., 2^128). Future specifications can define new AEAD algorithms which are key-committing. 9.5. Domain Separation HPKE allows combining a DHKEM variant "DHKEM(Group, KDF')" and a KDF such that both KDFs are instantiated by the same KDF. By design, the calls to "Extract()" and "Expand()" inside DHKEM and the remainder of HPKE use separate input domains. This justifies modeling them as independent functions even if instantiated by the same KDF. This domain separation between DHKEM and the remainder of HPKE is achieved Barnes, et al. Expires 27 November 2021 [Page 34] Internet-Draft HPKE May 2021 by the "suite_id" values in "LabeledExtract()" and "LabeledExpand()": The values used ("KEM..." in DHKEM and "HPKE..." in the remainder of HPKE) are prefix-free (a set is prefix-free if no element is a prefix of another within the set). Future KEM instantiations MUST ensure, should "Extract()" and "Expand()" be used internally, that they can be modeled as functions independent from the invocations of "Extract()" and "Expand()" in the remainder of HPKE. One way to ensure this is by using "LabeledExtract()" and "LabeledExpand()" with a "suite_id" as defined in Section 4, which will ensure input domain separation as outlined above. Particular attention needs to be paid if the KEM directly invokes functions that are used internally in HPKE's "Extract()" or "Expand()", such as "Hash()" and "HMAC()" in the case of HKDF. It MUST be ensured that inputs to these invocations cannot collide with inputs to the internal invocations of these functions inside "Extract()" or "Expand()". In HPKE's "KeySchedule()" this is avoided by using "Extract()" instead of "Hash()" on the arbitrary-length inputs "info" and "psk_id". The string literal "HPKE-v1" used in "LabeledExtract()" and "LabeledExpand()" ensures that any secrets derived in HPKE are bound to the scheme's name and version, even when possibly derived from the same Diffie-Hellman or KEM shared secret as in another scheme or version. 9.6. Application Embedding HPKE is designed to be a fairly low-level mechanism. As a result, it assumes that certain properties are provided by the application in which HPKE is embedded, and leaves certain security properties to be provided by other mechanisms. 9.6.1. External Requirements The primary requirement that HPKE imposes on applications is the requirement that ciphertexts MUST be presented to "ContextR.Open()" in the same order in which they were generated by "ContextS.Seal()". When the single-shot API is used (see Section 6), this is trivially true (since there is only ever one ciphertext. Applications that allow for multiple invocations of "Open()" / "Seal()" on the same context MUST enforce the ordering property described above. Barnes, et al. Expires 27 November 2021 [Page 35] Internet-Draft HPKE May 2021 Ordering requirements of this character are usually fulfilled by providing a sequence number in the framing of encrypted messages. Whatever information is used to determine the ordering of HPKE- encrypted messages SHOULD be included in the AAD passed to "ContextS.Seal()" and "ContextR.Open()". The specifics of this scheme are up to the application. HPKE is not tolerant of lost messages. Applications MUST be able to detect when a message has been lost. When an unrecoverable loss is detected, the application MUST discard any associated HPKE context. 9.6.2. Non-Goals HPKE does not provide several features that a more high-level protocol might provide, for example: * Downgrade prevention - HPKE assumes that the sender and recipient agree on what algorithms to use. Depending on how these algorithms are negotiated, it may be possible for an intermediary to force the two parties to use suboptimal algorithms. * Replay protection - The requirement that ciphertexts be presented to the "ContextR.Open()" function in the same order they were generated by "ContextS.Seal()" provides a degree of replay protection within a stream of ciphertexts resulting from a given context. HPKE provides no other replay protection. * Forward secrecy - HPKE ciphertexts are not forward-secure. In the Base and Auth modes, a given ciphertext can be decrypted if the recipient's public encryption key is compromised. In the PSK and AuthPSK modes, a given ciphertext can be decrypted if the recipient's private key and the PSK are compromised. * Hiding plaintext length - AEAD ciphertexts produced by HPKE do not hide the plaintext length. Applications requiring this level of privacy should use a suitable padding mechanism. See [I-D.ietf-tls-esni] and [RFC8467] for examples of protocol- specific padding policies. 9.7. Bidirectional Encryption As discussed in Section 5.2, HPKE encryption is unidirectional from sender to recipient. Applications that require bidirectional encryption can derive necessary keying material with the Secret Export interface Section 5.3. The type and length of such keying material depends on the application use case. Barnes, et al. Expires 27 November 2021 [Page 36] Internet-Draft HPKE May 2021 As an example, if an application needs AEAD encryption from recipient to sender, it can derive a key and nonce from the corresponding HPKE context as follows: key = context.Export("response key", Nk) nonce = context.Export("response nonce", Nn) In this example, the length of each secret is based on the AEAD algorithm used for the corresponding HPKE context. Note that HPKE's limitations with regard to sender authentication become limits on recipient authentication in this context. In particular, in the Base mode, there is no authentication of the remote party at all. Even in the Auth mode, where the remote party has proven that they hold a specific private key, this authentication is still subject to Key-Compromise Impersonation, as discussed in Section 9.1.1. 9.8. Metadata Protection The authenticated modes of HPKE (PSK, Auth, AuthPSK) require that the recipient know what key material to use for the sender. This can be signaled in applications by sending the PSK ID ("psk_id" above) and/ or the sender's public key ("pkS"). However, these values themselves might be considered sensitive, since in a given application context, they might identify the sender. An application that wishes to protect these metadata values without requiring further provisioning of keys can use an additional instance of HPKE, using the unauthenticated Base mode. Where the application might have sent "(psk_id, pkS, enc, ciphertext)" before, it would now send "(enc2, ciphertext2, enc, ciphertext)", where "(enc2, ciphertext2)" represent the encryption of the "psk_id" and "pkS" values. The cost of this approach is an additional KEM operation each for the sender and the recipient. A potential lower-cost approach (involving only symmetric operations) would be available if the nonce-protection schemes in [BNT19] could be extended to cover other metadata. However, this construction would require further analysis. Barnes, et al. Expires 27 November 2021 [Page 37] Internet-Draft HPKE May 2021 10. Message Encoding This document does not specify a wire format encoding for HPKE messages. Applications that adopt HPKE must therefore specify an unambiguous encoding mechanism which includes, minimally: the encapsulated value "enc", ciphertext value(s) (and order if there are multiple), and any info values that are not implicit. One example of a non-implicit value is the recipient public key used for encapsulation, which may be needed if a recipient has more than one public key. 11. IANA Considerations This document requests the creation of three new IANA registries: * HPKE KEM Identifiers * HPKE KDF Identifiers * HPKE AEAD Identifiers All these registries should be under a heading of "Hybrid Public Key Encryption", and administered under a Specification Required policy [RFC8126] 11.1. KEM Identifiers The "HPKE KEM Identifiers" registry lists identifiers for key encapsulation algorithms defined for use with HPKE. These are two- byte values, so the maximum possible value is 0xFFFF = 65535. Template: * Value: The two-byte identifier for the algorithm * KEM: The name of the algorithm * Nsecret: The length in bytes of a KEM shared secret produced by the algorithm * Nenc: The length in bytes of an encoded encapsulated key produced by the algorithm * Npk: The length in bytes of an encoded public key for the algorithm * Nsk: The length in bytes of an encoded private key for the algorithm Barnes, et al. Expires 27 November 2021 [Page 38] Internet-Draft HPKE May 2021 * Auth: A boolean indicating if this algorithm provides the "AuthEncap()"/"AuthDecap()" interface * Reference: Where this algorithm is defined Initial contents: Provided in Table 2 11.2. KDF Identifiers The "HPKE KDF Identifiers" registry lists identifiers for key derivation functions defined for use with HPKE. These are two-byte values, so the maximum possible value is 0xFFFF = 65535. Template: * Value: The two-byte identifier for the algorithm * KDF: The name of the algorithm * Nh: The output size of the Extract function in bytes * Reference: Where this algorithm is defined Initial contents: Provided in Table 3 11.3. AEAD Identifiers The "HPKE AEAD Identifiers" registry lists identifiers for authenticated encryption with associated data (AEAD) algorithms defined for use with HPKE. These are two-byte values, so the maximum possible value is 0xFFFF = 65535. Template: * Value: The two-byte identifier for the algorithm * AEAD: The name of the algorithm * Nk: The length in bytes of a key for this algorithm * Nn: The length in bytes of a nonce for this algorithm * Reference: Where this algorithm is defined Initial contents: Provided in Table 5 Barnes, et al. Expires 27 November 2021 [Page 39] Internet-Draft HPKE May 2021 12. Acknowledgements The authors would like to thank Joel Alwen, Jean-Philippe Aumasson, David Benjamin, Benjamin Beurdouche, Bruno Blanchet, Frank Denis, Stephen Farrell, Scott Fluhrer, Eduard Hauck, Scott Hollenbeck, Kevin Jacobs, Burt Kaliski, Eike Kiltz, Julia Len, John Mattsson, Christopher Patton, Doreen Riepel, Raphael Robert, Michael Rosenberg, Michael Scott, Martin Thomson, Steven Valdez, Riad Wahby, and other contributors in the CFRG for helpful feedback that greatly improved this document. 13. References 13.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5116] McGrew, D., "An Interface and Algorithms for Authenticated Encryption", RFC 5116, DOI 10.17487/RFC5116, January 2008, . [RFC8017] Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch, "PKCS #1: RSA Cryptography Specifications Version 2.2", RFC 8017, DOI 10.17487/RFC8017, November 2016, . [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 13.2. Informative References [ABHKLR20] Alwen, J., Blanchet, B., Hauck, E., Kiltz, E., Lipp, B., and D. Riepel, "Analysing the HPKE Standard", 2020, . [ANSI] American National Standards Institute, "ANSI X9.63 Public Key Cryptography for the Financial Services Industry -- Key Agreement and Key Transport Using Elliptic Curve Cryptography", 2001. Barnes, et al. Expires 27 November 2021 [Page 40] Internet-Draft HPKE May 2021 [BHK09] Mihir Bellare, ., Dennis Hofheinz, ., and . Eike Kiltz, "Subtleties in the Definition of IND-CCA: When and How Should Challenge-Decryption be Disallowed?", 2009, . [BJM97] Blake-Wilson, S., Johnson, D., and A. Menezes, "Key agreement protocols and their security analysis: Extended Abstract", DOI 10.1007/bfb0024447, Crytography and Coding pp. 30-45, 1997, . [BNT19] Bellare, M., Ng, R., and B. Tackmann, "Nonces Are Noticed: AEAD Revisited", 2019, . [CS01] Cramer, R. and V. Shoup, "Design and Analysis of Practical Public-Key Encryption Schemes Secure against Adaptive Chosen Ciphertext Attack", 2001, . [GAP] Okamoto, T. and D. Pointcheval, "The Gap-Problems - a New Class of Problems for the Security of Cryptographic Schemes", ISBN 978-3-540-44586-9, 2001, . [GCM] Dworkin, M., "Recommendation for block cipher modes of operation :: GaloisCounter Mode (GCM) and GMAC", DOI 10.6028/nist.sp.800-38d, National Institute of Standards and Technology report, 2007, . [HHK06] Herranz, J., Hofheinz, D., and E. Kiltz, "Some (in)sufficient conditions for secure hybrid encryption", 2006, . [HPKEAnalysis] Lipp, B., "An Analysis of Hybrid Public Key Encryption", 2020, . [I-D.ietf-mls-protocol] Barnes, R., Beurdouche, B., Millican, J., Omara, E., Cohn- Gordon, K., and R. Robert, "The Messaging Layer Security (MLS) Protocol", Work in Progress, Internet-Draft, draft- ietf-mls-protocol-11, 22 December 2020, . Barnes, et al. Expires 27 November 2021 [Page 41] Internet-Draft HPKE May 2021 [I-D.ietf-tls-esni] Rescorla, E., Oku, K., Sullivan, N., and C. A. Wood, "TLS Encrypted Client Hello", Work in Progress, Internet-Draft, draft-ietf-tls-esni-10, 8 March 2021, . [IEEE1363] Institute of Electrical and Electronics Engineers, "IEEE 1363a, Standard Specifications for Public Key Cryptography - Amendment 1 -- Additional Techniques"", 2004. [IMB] Diffie, W., Van Oorschot, P., and M. Wiener, "Authentication and authenticated key exchanges", DOI 10.1007/bf00124891, Designs, Codes and Cryptography Vol. 2, pp. 107-125, June 1992, . [ISO] International Organization for Standardization / International Electrotechnical Commission, "ISO/IEC 18033-2, Information Technology - Security Techniques - Encryption Algorithms - Part 2 -- Asymmetric Ciphers", 2006. [keyagreement] Barker, E., Chen, L., Roginsky, A., Vassilev, A., and R. Davis, "Recommendation for pair-wise key-establishment schemes using discrete logarithm cryptography", DOI 10.6028/nist.sp.800-56ar3, National Institute of Standards and Technology report, April 2018, . [LGR20] Len, J., Grubbs, P., and T. Ristenpart, "Partitioning Oracle Attacks". [MAEA10] Gayoso Martinez, V., Hernandez Alvarez, F., Hernandez Encinas, L., and C. Sanchez Avila, "A Comparison of the Standardized Versions of ECIES", 2010, . [NaCl] "Public-key authenticated encryption: crypto_box", 2019, . [NISTCurves] "Digital Signature Standard (DSS)", DOI 10.6028/nist.fips.186-4, National Institute of Standards and Technology report, July 2013, . Barnes, et al. Expires 27 November 2021 [Page 42] Internet-Draft HPKE May 2021 [RFC1421] Linn, J., "Privacy Enhancement for Internet Electronic Mail: Part I: Message Encryption and Authentication Procedures", RFC 1421, DOI 10.17487/RFC1421, February 1993, . [RFC5869] Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)", RFC 5869, DOI 10.17487/RFC5869, May 2010, . [RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves for Security", RFC 7748, DOI 10.17487/RFC7748, January 2016, . [RFC8439] Nir, Y. and A. Langley, "ChaCha20 and Poly1305 for IETF Protocols", RFC 8439, DOI 10.17487/RFC8439, June 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8467] Mayrhofer, A., "Padding Policies for Extension Mechanisms for DNS (EDNS(0))", RFC 8467, DOI 10.17487/RFC8467, October 2018, . [SECG] "Elliptic Curve Cryptography, Standards for Efficient Cryptography Group, ver. 2", 2009, . [SigncryptionDZ10] "Practical Signcryption", DOI 10.1007/978-3-540-89411-7, Information Security and Cryptography, 2010, . [TestVectors] "HPKE Test Vectors", 2021, . [WireGuard] Donenfeld, J.A., "WireGuard: Next Generation Kernel Network Tunnel", 2020, . Barnes, et al. Expires 27 November 2021 [Page 43] Internet-Draft HPKE May 2021 Appendix A. Test Vectors Each section below contains test vectors for a single HPKE ciphersuite and contains the following values: 1. Configuration information and private key material: This includes the "mode", "info" string, HPKE ciphersuite identifiers ("kem_id", "kdf_id", "aead_id"), and all sender, recipient, and ephemeral key material. For each role X, where X is one of S, R, or E as sender, recipient, and ephemeral, respectively, key pairs are generated as "(skX, pkX) = DeriveKeyPair(ikmX)". Each key pair "(skX, pkX)" is written in its serialized form, where "skXm = SerializePrivateKey(skX)" and "pkXm = SerializePublicKey(pkX)". For applicable modes, the shared PSK and PSK identifier are also included. 2. Context creation intermediate values and outputs: This includes the KEM outputs "enc" and "shared_secret" used to create the context, along with intermediate values "key_schedule_context" and "secret" computed in the KeySchedule function in Section 5.1. The outputs include the context values "key", "base_nonce", and "exporter_secret". 3. Encryption test vectors: A fixed plaintext message is encrypted using different sequence numbers and AAD values using the context computed in (2). Each test vector lists the sequence number and corresponding nonce computed with "base_nonce", the plaintext message "pt", AAD "aad", and output ciphertext "ct". 4. Export test vectors: Several exported values of the same length with differing context parameters are computed using the context computed in (2). Each test vector lists the "exporter_context", output length "L", and resulting export value. These test vectors are also available in JSON format at [TestVectors]. A.1. DHKEM(X25519, HKDF-SHA256), HKDF-SHA256, AES-128-GCM A.1.1. Base Setup Information Barnes, et al. Expires 27 November 2021 [Page 44] Internet-Draft HPKE May 2021 mode: 0 kem_id: 32 kdf_id: 1 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 7268600d403fce431561aef583ee1613527cff655c1343f29812e66706df3234 pkEm: 37fda3567bdbd628e88668c3c8d7e97d1d1253b6d4ea6d44c150f741f1bf4431 skEm: 52c4a758a802cd8b936eceea314432798d5baf2d7e9235dc084ab1b9cfa2f736 ikmR: 6db9df30aa07dd42ee5e8181afdb977e538f5e1fec8a06223f33f7013e525037 pkRm: 3948cfe0ad1ddb695d780e59077195da6c56506b027329794ab02bca80815c4d skRm: 4612c550263fc8ad58375df3f557aac531d26850903e55a9f23f21d8534e8ac8 enc: 37fda3567bdbd628e88668c3c8d7e97d1d1253b6d4ea6d44c150f741f1bf4431 shared_secret: fe0e18c9f024ce43799ae393c7e8fe8fce9d218875e8227b0187c04e7d2ea1fc key_schedule_context: 00725611c9d98c07c03f60095cd32d400d8347d45ed67097bb ad50fc56da742d07cb6cffde367bb0565ba28bb02c90744a20f5ef37f30523526106f637 abb05449 secret: 12fff91991e93b48de37e7daddb52981084bd8aa64289c3788471d9a9712f397 key: 4531685d41d65f03dc48f6b8302c05b0 base_nonce: 56d890e5accaaf011cff4b7d exporter_secret: 45ff1c2e220db587171952c0592d5f5ebe103f1561a2614e38f2ffd47e99e3f8 A.1.1.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 45] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 56d890e5accaaf011cff4b7d ct: f938558b5d72f1a23810b4be2ab4f84331acc02fc97babc53a52ae8218a355a96d87 70ac83d07bea87e13c512a sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 56d890e5accaaf011cff4b7c ct: af2d7e9ac9ae7e270f46ba1f975be53c09f8d875bdc8535458c2494e8a6eab251c03 d0c22a56b8ca42c2063b84 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 56d890e5accaaf011cff4b7f ct: 498dfcabd92e8acedc281e85af1cb4e3e31c7dc394a1ca20e173cb72516491588d96 a19ad4a683518973dcc180 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 56d890e5accaaf011cff4b79 ct: 583bd32bc67a5994bb8ceaca813d369bca7b2a42408cddef5e22f880b631215a09fc 0012bc69fccaa251c0246d sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 56d890e5accaaf011cff4b82 ct: 7175db9717964058640a3a11fb9007941a5d1757fda1a6935c805c21af32505bf106 deefec4a49ac38d71c9e0a sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 56d890e5accaaf011cff4a7d ct: 957f9800542b0b8891badb026d79cc54597cb2d225b54c00c5238c25d05c30e3fbed a97d2e0e1aba483a2df9f2 A.1.1.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 46] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 3853fe2b4035195a573ffc53856e77058e15d9ea064de3e59f4961d0095250ee exporter_context: 00 L: 32 exported_value: 2e8f0b54673c7029649d4eb9d5e33bf1872cf76d623ff164ac185da9e88c21a5 exporter_context: 54657374436f6e74657874 L: 32 exported_value: e9e43065102c3836401bed8c3c3c75ae46be1639869391d62c61f1ec7af54931 A.1.2. PSK Setup Information mode: 1 kem_id: 32 kdf_id: 1 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 78628c354e46f3e169bd231be7b2ff1c77aa302460a26dbfa15515684c00130b pkEm: 0ad0950d9fb9588e59690b74f1237ecdf1d775cd60be2eca57af5a4b0471c91b skEm: 463426a9ffb42bb17dbe6044b9abd1d4e4d95f9041cef0e99d7824eef2b6f588 ikmR: d4a09d09f575fef425905d2ab396c1449141463f698f8efdb7accfaff8995098 pkRm: 9fed7e8c17387560e92cc6462a68049657246a09bfa8ade7aefe589672016366 skRm: c5eb01eb457fe6c6f57577c5413b931550a162c71a03ac8d196babbd4e5ce0fd psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 0ad0950d9fb9588e59690b74f1237ecdf1d775cd60be2eca57af5a4b0471c91b shared_secret: 727699f009ffe3c076315019c69648366b69171439bd7dd0807743bde76986cd key_schedule_context: 01e78d5cf6190d275863411ff5edd0dece5d39fa48e04eec1e d9b71be34729d18ccb6cffde367bb0565ba28bb02c90744a20f5ef37f30523526106f637 abb05449 secret: 3728ab0b024b383b0381e432b47cced1496d2516957a76e2a9f5c8cb947afca4 key: 15026dba546e3ae05836fc7de5a7bb26 base_nonce: 9518635eba129d5ce0914555 exporter_secret: 3d76025dbbedc49448ec3f9080a1abab6b06e91c0b11ad23c912f043a0ee7655 A.1.2.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 47] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 9518635eba129d5ce0914555 ct: e52c6fed7f758d0cf7145689f21bc1be6ec9ea097fef4e959440012f4feb73fb611b 946199e681f4cfc34db8ea sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 9518635eba129d5ce0914554 ct: 49f3b19b28a9ea9f43e8c71204c00d4a490ee7f61387b6719db765e948123b45b616 33ef059ba22cd62437c8ba sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 9518635eba129d5ce0914557 ct: 257ca6a08473dc851fde45afd598cc83e326ddd0abe1ef23baa3baa4dd8cde99fce2 c1e8ce687b0b47ead1adc9 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 9518635eba129d5ce0914551 ct: a71d73a2cd8128fcccbd328b9684d70096e073b59b40b55e6419c9c68ae21069c847 e2a70f5d8fb821ce3dfb1c sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 9518635eba129d5ce09145aa ct: 55f84b030b7f7197f7d7d552365b6b932df5ec1abacd30241cb4bc4ccea27bd2b518 766adfa0fb1b71170e9392 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 9518635eba129d5ce0914455 ct: c5bf246d4a790a12dcc9eed5eae525081e6fb541d5849e9ce8abd92a3bc1551776be a16b4a518f23e237c14b59 A.1.2.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 48] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: dff17af354c8b41673567db6259fd6029967b4e1aad13023c2ae5df8f4f43bf6 exporter_context: 00 L: 32 exported_value: 6a847261d8207fe596befb52928463881ab493da345b10e1dcc645e3b94e2d95 exporter_context: 54657374436f6e74657874 L: 32 exported_value: 8aff52b45a1be3a734bc7a41e20b4e055ad4c4d22104b0c20285a7c4302401cd A.1.3. Auth Setup Information mode: 2 kem_id: 32 kdf_id: 1 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 6e6d8f200ea2fb20c30b003a8b4f433d2f4ed4c2658d5bc8ce2fef718059c9f7 pkEm: 23fb952571a14a25e3d678140cd0e5eb47a0961bb18afcf85896e5453c312e76 skEm: ff4442ef24fbc3c1ff86375b0be1e77e88a0de1e79b30896d73411c5ff4c3518 ikmR: f1d4a30a4cef8d6d4e3b016e6fd3799ea057db4f345472ed302a67ce1c20cdec pkRm: 1632d5c2f71c2b38d0a8fcc359355200caa8b1ffdf28618080466c909cb69b2e skRm: fdea67cf831f1ca98d8e27b1f6abeb5b7745e9d35348b80fa407ff6958f9137e ikmS: 94b020ce91d73fca4649006c7e7329a67b40c55e9e93cc907d282bbbff386f58 pkSm: 8b0c70873dc5aecb7f9ee4e62406a397b350e57012be45cf53b7105ae731790b skSm: dc4a146313cce60a278a5323d321f051c5707e9c45ba21a3479fecdf76fc69dd enc: 23fb952571a14a25e3d678140cd0e5eb47a0961bb18afcf85896e5453c312e76 shared_secret: 2d6db4cf719dc7293fcbf3fa64690708e44e2bebc81f84608677958c0d4448a7 key_schedule_context: 02725611c9d98c07c03f60095cd32d400d8347d45ed67097bb ad50fc56da742d07cb6cffde367bb0565ba28bb02c90744a20f5ef37f30523526106f637 abb05449 secret: 56c62333d9d9f7767f5b083fdfce0aa7e57e301b74029bb0cffa7331385f1dda key: b062cb2c4dd4bca0ad7c7a12bbc341e6 base_nonce: a1bc314c1942ade7051ffed0 exporter_secret: ee1a093e6e1c393c162ea98fdf20560c75909653550540a2700511b65c88c6f1 A.1.3.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 49] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: a1bc314c1942ade7051ffed0 ct: 5fd92cc9d46dbf8943e72a07e42f363ed5f721212cd90bcfd072bfd9f44e06b80fd1 7824947496e21b680c141b sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: a1bc314c1942ade7051ffed1 ct: d3736bb256c19bfa93d79e8f80b7971262cb7c887e35c26370cfed62254369a1b52e 3d505b79dd699f002bc8ed sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: a1bc314c1942ade7051ffed2 ct: 122175cfd5678e04894e4ff8789e85dd381df48dcaf970d52057df2c9acc3b121313 a2bfeaa986050f82d93645 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: a1bc314c1942ade7051ffed4 ct: dae12318660cf963c7bcbef0f39d64de3bf178cf9e585e756654043cc5059873bc8a f190b72afc43d1e0135ada sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: a1bc314c1942ade7051ffe2f ct: 55d53d85fe4d9e1e97903101eab0b4865ef20cef28765a47f840ff99625b7d69dee9 27df1defa66a036fc58ff2 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: a1bc314c1942ade7051fffd0 ct: 42fa248a0e67ccca688f2b1d13ba4ba84755acf764bd797c8f7ba3b9b1dc3330326f 8d172fef6003c79ec72319 A.1.3.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 50] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 28c70088017d70c896a8420f04702c5a321d9cbf0279fba899b59e51bac72c85 exporter_context: 00 L: 32 exported_value: 25dfc004b0892be1888c3914977aa9c9bbaf2c7471708a49e1195af48a6f29ce exporter_context: 54657374436f6e74657874 L: 32 exported_value: 5a0131813abc9a522cad678eb6bafaabc43389934adb8097d23c5ff68059eb64 A.1.4. AuthPSK Setup Information mode: 3 kem_id: 32 kdf_id: 1 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 4303619085a20ebcf18edd22782952b8a7161e1dbae6e46e143a52a96127cf84 pkEm: 820818d3c23993492cc5623ab437a48a0a7ca3e9639c140fe1e33811eb844b7c skEm: 14de82a5897b613616a00c39b87429df35bc2b426bcfd73febcb45e903490768 ikmR: 4b16221f3b269a88e207270b5e1de28cb01f847841b344b8314d6a622fe5ee90 pkRm: 1d11a3cd247ae48e901939659bd4d79b6b959e1f3e7d66663fbc9412dd4e0976 skRm: cb29a95649dc5656c2d054c1aa0d3df0493155e9d5da6d7e344ed8b6a64a9423 ikmS: 62f77dcf5df0dd7eac54eac9f654f426d4161ec850cc65c54f8b65d2e0b4e345 pkSm: 2bfb2eb18fcad1af0e4f99142a1c474ae74e21b9425fc5c589382c69b50cc57e skSm: fc1c87d2f3832adb178b431fce2ac77c7ca2fd680f3406c77b5ecdf818b119f4 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 820818d3c23993492cc5623ab437a48a0a7ca3e9639c140fe1e33811eb844b7c shared_secret: f9d0e870aba28d04709b2680cb8185466c6a6ff1d6e9d1091d5bf5e10ce3a577 key_schedule_context: 03e78d5cf6190d275863411ff5edd0dece5d39fa48e04eec1e d9b71be34729d18ccb6cffde367bb0565ba28bb02c90744a20f5ef37f30523526106f637 abb05449 secret: 5f96c55e4108c6691829aaabaa7d539c0b41d7c72aae94ae289752f056b6cec4 key: 1364ead92c47aa7becfa95203037b19a base_nonce: 99d8b5c54669807e9fc70df1 exporter_secret: f048d55eacbf60f9c6154bd4021774d1075ebf963c6adc71fa846f183ab2dde6 A.1.4.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 51] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 99d8b5c54669807e9fc70df1 ct: a84c64df1e11d8fd11450039d4fe64ff0c8a99fca0bd72c2d4c3e0400bc14a40f27e 45e141a24001697737533e sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 99d8b5c54669807e9fc70df0 ct: 4d19303b848f424fc3c3beca249b2c6de0a34083b8e909b6aa4c3688505c05ffe0c8 f57a0a4c5ab9da127435d9 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 99d8b5c54669807e9fc70df3 ct: 0c085a365fbfa63409943b00a3127abce6e45991bc653f182a80120868fc507e9e4d 5e37bcc384fc8f14153b24 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 99d8b5c54669807e9fc70df5 ct: 000a3cd3a3523bf7d9796830b1cd987e841a8bae6561ebb6791a3f0e34e89a4fb539 faeee3428b8bbc082d2c1a sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 99d8b5c54669807e9fc70d0e ct: 576d39dd2d4cc77d1a14a51d5c5f9d5e77586c3d8d2ab33bdec6379e28ce5c502f0b 1cbd09047cf9eb9269bb52 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 99d8b5c54669807e9fc70cf1 ct: 13239bab72e25e9fd5bb09695d23c90a24595158b99127505c8a9ff9f127e0d657f7 1af59d67d4f4971da028f9 A.1.4.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 52] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 08f7e20644bb9b8af54ad66d2067457c5f9fcb2a23d9f6cb4445c0797b330067 exporter_context: 00 L: 32 exported_value: 52e51ff7d436557ced5265ff8b94ce69cf7583f49cdb374e6aad801fc063b010 exporter_context: 54657374436f6e74657874 L: 32 exported_value: a30c20370c026bbea4dca51cb63761695132d342bae33a6a11527d3e7679436d A.2. DHKEM(X25519, HKDF-SHA256), HKDF-SHA256, ChaCha20Poly1305 A.2.1. Base Setup Information mode: 0 kem_id: 32 kdf_id: 1 aead_id: 3 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 909a9b35d3dc4713a5e72a4da274b55d3d3821a37e5d099e74a647db583a904b pkEm: 1afa08d3dec047a643885163f1180476fa7ddb54c6a8029ea33f95796bf2ac4a skEm: f4ec9b33b792c372c1d2c2063507b684ef925b8c75a42dbcbf57d63ccd381600 ikmR: 1ac01f181fdf9f352797655161c58b75c656a6cc2716dcb66372da835542e1df pkRm: 4310ee97d88cc1f088a5576c77ab0cf5c3ac797f3d95139c6c84b5429c59662a skRm: 8057991eef8f1f1af18f4a9491d16a1ce333f695d4db8e38da75975c4478e0fb enc: 1afa08d3dec047a643885163f1180476fa7ddb54c6a8029ea33f95796bf2ac4a shared_secret: 0bbe78490412b4bbea4812666f7916932b828bba79942424abb65244930d69a7 key_schedule_context: 00431df6cd95e11ff49d7013563baf7f11588c75a6611ee2a4 404a49306ae4cfc5b69c5718a60cc5876c358d3f7fc31ddb598503f67be58ea1e798c0bb 19eb9796 secret: 5b9cd775e64b437a2335cf499361b2e0d5e444d5cb41a8a53336d8fe402282c6 key: ad2744de8e17f4ebba575b3f5f5a8fa1f69c2a07f6e7500bc60ca6e3e3ec1c91 base_nonce: 5c4d98150661b848853b547f exporter_secret: a3b010d4994890e2c6968a36f64470d3c824c8f5029942feb11e7a74b2921922 A.2.1.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 53] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 5c4d98150661b848853b547f ct: 1c5250d8034ec2b784ba2cfd69dbdb8af406cfe3ff938e131f0def8c8b60b4db2199 3c62ce81883d2dd1b51a28 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 5c4d98150661b848853b547e ct: 6b53c051e4199c518de79594e1c4ab18b96f081549d45ce015be002090bb119e8528 5337cc95ba5f59992dc98c sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 5c4d98150661b848853b547d ct: 71146bd6795ccc9c49ce25dda112a48f202ad220559502cef1f34271e0cb4b02b4f1 0ecac6f48c32f878fae86b sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 5c4d98150661b848853b547b ct: 63357a2aa291f5a4e5f27db6baa2af8cf77427c7c1a909e0b37214dd47db122bb153 495ff0b02e9e54a50dbe16 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 5c4d98150661b848853b5480 ct: 18ab939d63ddec9f6ac2b60d61d36a7375d2070c9b683861110757062c52b8880a5f 6b3936da9cd6c23ef2a95c sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 5c4d98150661b848853b557f ct: 7a4a13e9ef23978e2c520fd4d2e757514ae160cd0cd05e556ef692370ca53076214c 0c40d4c728d6ed9e727a5b A.2.1.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 54] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 4bbd6243b8bb54cec311fac9df81841b6fd61f56538a775e7c80a9f40160606e exporter_context: 00 L: 32 exported_value: 8c1df14732580e5501b00f82b10a1647b40713191b7c1240ac80e2b68808ba69 exporter_context: 54657374436f6e74657874 L: 32 exported_value: 5acb09211139c43b3090489a9da433e8a30ee7188ba8b0a9a1ccf0c229283e53 A.2.2. PSK Setup Information mode: 1 kem_id: 32 kdf_id: 1 aead_id: 3 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 35706a0b09fb26fb45c39c2f5079c709c7cf98e43afa973f14d88ece7e29c2e3 pkEm: 2261299c3f40a9afc133b969a97f05e95be2c514e54f3de26cbe5644ac735b04 skEm: 0c35fdf49df7aa01cd330049332c40411ebba36e0c718ebc3edf5845795f6321 ikmR: 26b923eade72941c8a85b09986cdfa3f1296852261adedc52d58d2930269812b pkRm: 13640af826b722fc04feaa4de2f28fbd5ecc03623b317834e7ff4120dbe73062 skRm: 77d114e0212be51cb1d76fa99dd41cfd4d0166b08caa09074430a6c59ef17879 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 2261299c3f40a9afc133b969a97f05e95be2c514e54f3de26cbe5644ac735b04 shared_secret: 4be079c5e77779d0215b3f689595d59e3e9b0455d55662d1f3666ec606e50ea7 key_schedule_context: 016870c4c76ca38ae43efbec0f2377d109499d7ce73f4a9e1e c37f21d3d063b97cb69c5718a60cc5876c358d3f7fc31ddb598503f67be58ea1e798c0bb 19eb9796 secret: 16974354c497c9bd24c000ceed693779b604f1944975b18c442d373663f4a8cc key: 600d2fdb0313a7e5c86a9ce9221cd95bed069862421744cfb4ab9d7203a9c019 base_nonce: 112e0465562045b7368653e7 exporter_secret: 73b506dc8b6b4269027f80b0362def5cbb57ee50eed0c2873dac9181f453c5ac A.2.2.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 55] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 112e0465562045b7368653e7 ct: 4a177f9c0d6f15cfdf533fb65bf84aecdc6ab16b8b85b4cf65a370e07fc1d78d28fb 073214525276f4a89608ff sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 112e0465562045b7368653e6 ct: 5c3cabae2f0b3e124d8d864c116fd8f20f3f56fda988c3573b40b09997fd6c769e77 c8eda6cda4f947f5b704a8 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 112e0465562045b7368653e5 ct: 14958900b44bdae9cbe5a528bf933c5c990dbb8e282e6e495adf8205d19da9eb270e 3a6f1e0613ab7e757962a4 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 112e0465562045b7368653e3 ct: c2a7bc09ddb853cf2effb6e8d058e346f7fe0fb3476528c80db6b698415c5f8c50b6 8a9a355609e96d2117f8d3 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 112e0465562045b736865318 ct: 2414d0788e4bc39a59a26d7bd5d78e111c317d44c37bd5a4c2a1235f2ddc2085c487 d406490e75210c958724a7 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 112e0465562045b7368652e7 ct: c567ae1c3f0f75abe1dd9e4532b422600ed4a6e5b9484dafb1e43ab9f5fd662b28c0 0e2e81d3cde955dae7e218 A.2.2.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 56] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 813c1bfc516c99076ae0f466671f0ba5ff244a41699f7b2417e4c59d46d39f40 exporter_context: 00 L: 32 exported_value: 2745cf3d5bb65c333658732954ee7af49eb895ce77f8022873a62a13c94cb4e1 exporter_context: 54657374436f6e74657874 L: 32 exported_value: ad40e3ae14f21c99bfdebc20ae14ab86f4ca2dc9a4799d200f43a25f99fa78ae A.2.3. Auth Setup Information mode: 2 kem_id: 32 kdf_id: 1 aead_id: 3 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 938d3daa5a8904540bc24f48ae90eed3f4f7f11839560597b55e7c9598c996c0 pkEm: f7674cc8cd7baa5872d1f33dbaffe3314239f6197ddf5ded1746760bfc847e0e skEm: c94619e1af28971c8fa7957192b7e62a71ca2dcdde0a7cc4a8a9e741d600ab13 ikmR: 64835d5ee64aa7aad57c6f2e4f758f7696617f8829e70bc9ac7a5ef95d1c756c pkRm: 1a478716d63cb2e16786ee93004486dc151e988b34b475043d3e0175bdb01c44 skRm: 3ca22a6d1cda1bb9480949ec5329d3bf0b080ca4c45879c95eddb55c70b80b82 ikmS: 9d8f94537d5a3ddef71234c0baedfad4ca6861634d0b94c3007fed557ad17df6 pkSm: f0f4f9e96c54aeed3f323de8534fffd7e0577e4ce269896716bcb95643c8712b skSm: 2def0cb58ffcf83d1062dd085c8aceca7f4c0c3fd05912d847b61f3e54121f05 enc: f7674cc8cd7baa5872d1f33dbaffe3314239f6197ddf5ded1746760bfc847e0e shared_secret: d2d67828c8bc9fa661cf15a31b3ebf1febe0cafef7abfaaca580aaf6d471e3eb key_schedule_context: 02431df6cd95e11ff49d7013563baf7f11588c75a6611ee2a4 404a49306ae4cfc5b69c5718a60cc5876c358d3f7fc31ddb598503f67be58ea1e798c0bb 19eb9796 secret: 3022dfc0a81d6e09a2e6daeeb605bb1ebb9ac49535540d9a4c6560064a6c6da8 key: b071fd1136680600eb447a845a967d35e9db20749cdf9ce098bcc4deef4b1356 base_nonce: d20577dff16d7cea2c4bf780 exporter_secret: be2d93b82071318cdb88510037cf504344151f2f9b9da8ab48974d40a2251dd7 A.2.3.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 57] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: d20577dff16d7cea2c4bf780 ct: ab1a13c9d4f01a87ec3440dbd756e2677bd2ecf9df0ce7ed73869b98e00c09be111c b9fdf077347aeb88e61bdf sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: d20577dff16d7cea2c4bf781 ct: 3265c7807ffff7fdace21659a2c6ccffee52a26d270c76468ed74202a65478bfaedf ff9c2b7634e24f10b71016 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: d20577dff16d7cea2c4bf782 ct: 3aadee86ad2a05081ea860033a9d09dbccb4acac2ded0891da40f51d4df19925f7a7 67b076a5cbc9355c8fd35e sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: d20577dff16d7cea2c4bf784 ct: 502ecccd5c2be3506a081809cc58b43b94f77cbe37b8b31712d9e21c9e61aa6946a8 e922f54eae630f88eb8033 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: d20577dff16d7cea2c4bf77f ct: 652e597ba20f3d9241cda61f33937298b1169e6adf72974bbe454297502eb4be132e 1c5064702fc165c2ddbde8 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: d20577dff16d7cea2c4bf680 ct: 3be14e8b3bbd1028cf2b7d0a691dbbeff71321e7dec92d3c2cfb30a0994ab246af76 168480285a60037b4ba13a A.2.3.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 58] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 070cffafd89b67b7f0eeb800235303a223e6ff9d1e774dce8eac585c8688c872 exporter_context: 00 L: 32 exported_value: 2852e728568d40ddb0edde284d36a4359c56558bb2fb8837cd3d92e46a3a14a8 exporter_context: 54657374436f6e74657874 L: 32 exported_value: 1df39dc5dd60edcbf5f9ae804e15ada66e885b28ed7929116f768369a3f950ee A.2.4. AuthPSK Setup Information mode: 3 kem_id: 32 kdf_id: 1 aead_id: 3 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 49d6eac8c6c558c953a0a252929a818745bb08cd3d29e15f9f5db5eb2e7d4b84 pkEm: 656a2e00dc9990fd189e6e473459392df556e9a2758754a09db3f51179a3fc02 skEm: 5e6dd73e82b856339572b7245d3cbb073a7561c0bee52873490e305cbb710410 ikmR: f3304ddcf15848488271f12b75ecaf72301faabf6ad283654a14c398832eb184 pkRm: a5099431c35c491ec62ca91df1525d6349cb8aa170c51f9581f8627be6334851 skRm: 7b36a42822e75bf3362dfabbe474b3016236408becb83b859a6909e22803cb0c ikmS: 20ade1d5203de1aadfb261c4700b6432e260d0d317be6ebbb8d7fffb1f86ad9d pkSm: 3ac5bd4dd66ff9f2740bef0d6ccb66daa77bff7849d7895182b07fb74d087c45 skSm: 90761c5b0a7ef0985ed66687ad708b921d9803d51637c8d1cb72d03ed0f64418 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 656a2e00dc9990fd189e6e473459392df556e9a2758754a09db3f51179a3fc02 shared_secret: 86a6c0ed17714f11d2951747e660857a5fd7616c933ef03207808b7a7123fe67 key_schedule_context: 036870c4c76ca38ae43efbec0f2377d109499d7ce73f4a9e1e c37f21d3d063b97cb69c5718a60cc5876c358d3f7fc31ddb598503f67be58ea1e798c0bb 19eb9796 secret: 22670daee17530c9564001d0a7e740e80d0bcc7ae15349f472fcc9e057cbc259 key: 49c7e6d7d2d257aded2a746fe6a9bf12d4de8007c4862b1fdffe8c35fb65054c base_nonce: abac79931e8c1bcb8a23960a exporter_secret: 7c6cc1bb98993cd93e2599322247a58fd41fdecd3db895fb4c5fd8d6bbe606b5 A.2.4.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 59] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: abac79931e8c1bcb8a23960a ct: 9aa52e29274fc6172e38a4461361d2342585d3aeec67fb3b721ecd63f059577c7fe8 86be0ede01456ebc67d597 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: abac79931e8c1bcb8a23960b ct: 59460bacdbe7a920ef2806a74937d5a691d6d5062d7daafcad7db7e4d8c649adffe5 75c1889c5c2e3a49af8e3e sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: abac79931e8c1bcb8a239608 ct: 5688ff6a03ba26ae936044a5c800f286fb5d1eccdd2a0f268f6ff9773b51169318d1 a1466bb36263415071db00 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: abac79931e8c1bcb8a23960e ct: d936b7a01f5c7dc4c3dc04e322cc694684ee18dd71719196874e5235aed3cfb06cad cd3bc7da0877488d7c551d sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: abac79931e8c1bcb8a2396f5 ct: 4d4c462f7b9b637eaf1f4e15e325b7bc629c0af6e3073422c86064cc3c98cff87300 f054fd56dd57dc34358beb sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: abac79931e8c1bcb8a23970a ct: 9b7f84224922d2a9edd7b2c2057f3bcf3a547f17570575e626202e593bfdd99e9878 a1af9e41ded58c7fb77d2f A.2.4.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 60] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: c23ebd4e7a0ad06a5dddf779f65004ce9481069ce0f0e6dd51a04539ddcbd5cd exporter_context: 00 L: 32 exported_value: ed7ff5ca40a3d84561067ebc8e01702bc36cf1eb99d42a92004642b9dfaadd37 exporter_context: 54657374436f6e74657874 L: 32 exported_value: d3bae066aa8da27d527d85c040f7dd6ccb60221c902ee36a82f70bcd62a60ee4 A.3. DHKEM(P-256, HKDF-SHA256), HKDF-SHA256, AES-128-GCM A.3.1. Base Setup Information mode: 0 kem_id: 16 kdf_id: 1 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 4270e54ffd08d79d5928020af4686d8f6b7d35dbe470265f1f5aa22816ce860e pkEm: 04a92719c6195d5085104f469a8b9814d5838ff72b60501e2c4466e5e67b325ac9 8536d7b61a1af4b78e5b7f951c0900be863c403ce65c9bfcb9382657222d18c4 skEm: 4995788ef4b9d6132b249ce59a77281493eb39af373d236a1fe415cb0c2d7beb ikmR: 668b37171f1072f3cf12ea8a236a45df23fc13b82af3609ad1e354f6ef817550 pkRm: 04fe8c19ce0905191ebc298a9245792531f26f0cece2460639e8bc39cb7f706a82 6a779b4cf969b8a0e539c7f62fb3d30ad6aa8f80e30f1d128aafd68a2ce72ea0 skRm: f3ce7fdae57e1a310d87f1ebbde6f328be0a99cdbcadf4d6589cf29de4b8ffd2 enc: 04a92719c6195d5085104f469a8b9814d5838ff72b60501e2c4466e5e67b325ac98 536d7b61a1af4b78e5b7f951c0900be863c403ce65c9bfcb9382657222d18c4 shared_secret: c0d26aeab536609a572b07695d933b589dcf363ff9d93c93adea537aeabb8cb8 key_schedule_context: 00b88d4e6d91759e65e87c470e8b9141113e9ad5f0c8ceefc1 e088c82e6980500798e486f9c9c09c9b5c753ac72d6005de254c607d1b534ed11d493ae1 c1d9ac85 secret: 2eb7b6bf138f6b5aff857414a058a3f1750054a9ba1f72c2cf0684a6f20b10e1 key: 868c066ef58aae6dc589b6cfdd18f97e base_nonce: 4e0bc5018beba4bf004cca59 exporter_secret: 14ad94af484a7ad3ef40e9f3be99ecc6fa9036df9d4920548424df127ee0d99f A.3.1.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 61] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 4e0bc5018beba4bf004cca59 ct: 5ad590bb8baa577f8619db35a36311226a896e7342a6d836d8b7bcd2f20b6c7f9076 ac232e3ab2523f39513434 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 4e0bc5018beba4bf004cca58 ct: fa6f037b47fc21826b610172ca9637e82d6e5801eb31cbd3748271affd4ecb06646e 0329cbdf3c3cd655b28e82 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 4e0bc5018beba4bf004cca5b ct: 895cabfac50ce6c6eb02ffe6c048bf53b7f7be9a91fc559402cbc5b8dcaeb52b2ccc 93e466c28fb55fed7a7fec sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 4e0bc5018beba4bf004cca5d ct: 8787491ee8df99bc99a246c4b3216d3d57ab5076e18fa27133f520703bc70ec999dd 36ce042e44f0c3169a6a8f sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 4e0bc5018beba4bf004ccaa6 ct: 2ad71c85bf3f45c6eca301426289854b31448bcf8a8ccb1deef3ebd87f60848aa53c 538c30a4dac71d619ee2cd sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 4e0bc5018beba4bf004ccb59 ct: 10f179686aa2caec1758c8e554513f16472bd0a11e2a907dde0b212cbe87d74f367f 8ffe5e41cd3e9962a6afb2 A.3.1.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 62] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 5e9bc3d236e1911d95e65b576a8a86d478fb827e8bdfe77b741b289890490d4d exporter_context: 00 L: 32 exported_value: 6cff87658931bda83dc857e6353efe4987a201b849658d9b047aab4cf216e796 exporter_context: 54657374436f6e74657874 L: 32 exported_value: d8f1ea7942adbba7412c6d431c62d01371ea476b823eb697e1f6e6cae1dab85a A.3.2. PSK Setup Information mode: 1 kem_id: 16 kdf_id: 1 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 2afa611d8b1a7b321c761b483b6a053579afa4f767450d3ad0f84a39fda587a6 pkEm: 04305d35563527bce037773d79a13deabed0e8e7cde61eecee403496959e89e4d0 ca701726696d1485137ccb5341b3c1c7aaee90a4a02449725e744b1193b53b5f skEm: 57427244f6cc016cddf1c19c8973b4060aa13579b4c067fd5d93a5d74e32a90f ikmR: d42ef874c1913d9568c9405407c805baddaffd0898a00f1e84e154fa787b2429 pkRm: 040d97419ae99f13007a93996648b2674e5260a8ebd2b822e84899cd52d87446ea 394ca76223b76639eccdf00e1967db10ade37db4e7db476261fcc8df97c5ffd1 skRm: 438d8bcef33b89e0e9ae5eb0957c353c25a94584b0dd59c991372a75b43cb661 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 04305d35563527bce037773d79a13deabed0e8e7cde61eecee403496959e89e4d0c a701726696d1485137ccb5341b3c1c7aaee90a4a02449725e744b1193b53b5f shared_secret: 2e783ad86a1beae03b5749e0f3f5e9bb19cb7eb382f2fb2dd64c99f15ae0661b key_schedule_context: 01b873cdf2dff4c1434988053b7a775e980dd2039ea24f950b 26b056ccedcb933198e486f9c9c09c9b5c753ac72d6005de254c607d1b534ed11d493ae1 c1d9ac85 secret: f2f534e55931c62eeb2188c1f53450354a725183937e68c85e68d6b267504d26 key: 55d9eb9d26911d4c514a990fa8d57048 base_nonce: b595dc6b2d7e2ed23af529b1 exporter_secret: 895a723a1eab809804973a53c0ee18ece29b25a7555a4808277ad2651d66d705 A.3.2.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 63] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: b595dc6b2d7e2ed23af529b1 ct: 90c4deb5b75318530194e4bb62f890b019b1397bbf9d0d6eb918890e1fb2be1ac260 3193b60a49c2126b75d0eb sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: b595dc6b2d7e2ed23af529b0 ct: 9e223384a3620f4a75b5a52f546b7262d8826dea18db5a365feb8b997180b22d72dc 1287f7089a1073a7102c27 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: b595dc6b2d7e2ed23af529b3 ct: adf9f6000773035023be7d415e13f84c1cb32a24339a32eb81df02be9ddc6abc880d d81cceb7c1d0c7781465b2 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: b595dc6b2d7e2ed23af529b5 ct: 1f4cc9b7013d65511b1f69c050b7bd8bbd5a5c16ece82b238fec4f30ba2400e7ca8e e482ac5253cffb5c3dc577 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: b595dc6b2d7e2ed23af5294e ct: cdc541253111ed7a424eea5134dc14fc5e8293ab3b537668b8656789628e45894e5b b873c968e3b7cdcbb654a4 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: b595dc6b2d7e2ed23af528b1 ct: faf985208858b1253b97b60aecd28bc18737b58d1242370e7703ec33b73a4c31a1af ee300e349adef9015bbbfd A.3.2.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 64] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: a115a59bf4dd8dc49332d6a0093af8efca1bcbfd3627d850173f5c4a55d0c185 exporter_context: 00 L: 32 exported_value: 4517eaede0669b16aac7c92d5762dd459c301fa10e02237cd5aeb9be969430c4 exporter_context: 54657374436f6e74657874 L: 32 exported_value: 164e02144d44b607a7722e58b0f4156e67c0c2874d74cf71da6ca48a4cbdc5e0 A.3.3. Auth Setup Information mode: 2 kem_id: 16 kdf_id: 1 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 798d82a8d9ea19dbc7f2c6dfa54e8a6706f7cdc119db0813dacf8440ab37c857 pkEm: 042224f3ea800f7ec55c03f29fc9865f6ee27004f818fcbdc6dc68932c1e52e15b 79e264a98f2c535ef06745f3d308624414153b22c7332bc1e691cb4af4d53454 skEm: 6b8de0873aed0c1b2d09b8c7ed54cbf24fdf1dfc7a47fa501f918810642d7b91 ikmR: 7bc93bde8890d1fb55220e7f3b0c107ae7e6eda35ca4040bb6651284bf0747ee pkRm: 04423e363e1cd54ce7b7573110ac121399acbc9ed815fae03b72ffbd4c18b01836 835c5a09513f28fc971b7266cfde2e96afe84bb0f266920e82c4f53b36e1a78d skRm: d929ab4be2e59f6954d6bedd93e638f02d4046cef21115b00cdda2acb2a4440e ikmS: 874baa0dcf93595a24a45a7f042e0d22d368747daaa7e19f80a802af19204ba8 pkSm: 04a817a0902bf28e036d66add5d544cc3a0457eab150f104285df1e293b5c10eef 8651213e43d9cd9086c80b309df22cf37609f58c1127f7607e85f210b2804f73 skSm: 1120ac99fb1fccc1e8230502d245719d1b217fe20505c7648795139d177f0de9 enc: 042224f3ea800f7ec55c03f29fc9865f6ee27004f818fcbdc6dc68932c1e52e15b7 9e264a98f2c535ef06745f3d308624414153b22c7332bc1e691cb4af4d53454 shared_secret: d4aea336439aadf68f9348880aa358086f1480e7c167b6ef15453ba69b94b44f key_schedule_context: 02b88d4e6d91759e65e87c470e8b9141113e9ad5f0c8ceefc1 e088c82e6980500798e486f9c9c09c9b5c753ac72d6005de254c607d1b534ed11d493ae1 c1d9ac85 secret: fd0a93c7c6f6b1b0dd6a822d7b16f6c61c83d98ad88426df4613c3581a2319f1 key: 19aa8472b3fdc530392b0e54ca17c0f5 base_nonce: b390052d26b67a5b8a8fcaa4 exporter_secret: f152759972660eb0e1db880835abd5de1c39c8e9cd269f6f082ed80e28acb164 Barnes, et al. Expires 27 November 2021 [Page 65] Internet-Draft HPKE May 2021 A.3.3.1. Encryptions sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: b390052d26b67a5b8a8fcaa4 ct: 82ffc8c44760db691a07c5627e5fc2c08e7a86979ee79b494a17cc3405446ac2bdb8 f265db4a099ed3289ffe19 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: b390052d26b67a5b8a8fcaa5 ct: b0a705a54532c7b4f5907de51c13dffe1e08d55ee9ba59686114b05945494d96725b 239468f1229e3966aa1250 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: b390052d26b67a5b8a8fcaa6 ct: 8dc805680e3271a801790833ed74473710157645584f06d1b53ad439078d880b23e2 5256663178271c80ee8b7c sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: b390052d26b67a5b8a8fcaa0 ct: 04c8f7aae1584b61aa5816382cb0b834a5d744f420e6dffb5ddcec633a21b8b34728 20930c1ea9258b035937a2 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: b390052d26b67a5b8a8fca5b ct: 4a319462eaedee37248b4d985f64f4f863d31913fe9e30b6e13136053b69fe5d7085 3c84c60a84bb5495d5a678 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: b390052d26b67a5b8a8fcba4 ct: 28e874512f8940fafc7d06135e7589f6b4198bc0f3a1c64702e72c9e6abaf9f05cb0 d2f11b03a517898815c934 A.3.3.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 66] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 837e49c3ff629250c8d80d3c3fb957725ed481e59e2feb57afd9fe9a8c7c4497 exporter_context: 00 L: 32 exported_value: 594213f9018d614b82007a7021c3135bda7b380da4acd9ab27165c508640dbda exporter_context: 54657374436f6e74657874 L: 32 exported_value: 14fe634f95ca0d86e15247cca7de7ba9b73c9b9deb6437e1c832daf7291b79d5 A.3.4. AuthPSK Setup Information mode: 3 kem_id: 16 kdf_id: 1 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 3c1fceb477ec954c8d58ef3249e4bb4c38241b5925b95f7486e4d9f1d0d35fbb pkEm: 046a1de3fc26a3d43f4e4ba97dbe24f7e99181136129c48fbe872d4743e2b13135 7ed4f29a7b317dc22509c7b00991ae990bf65f8b236700c82ab7c11a84511401 skEm: 36f771e411cf9cf72f0701ef2b991ce9743645b472e835fe234fb4d6eb2ff5a0 ikmR: abcc2da5b3fa81d8aabd91f7f800a8ccf60ec37b1b585a5d1d1ac77f258b6cca pkRm: 04d824d7e897897c172ac8a9e862e4bd820133b8d090a9b188b8233a64dfbc5f72 5aa0aa52c8462ab7c9188f1c4872f0c99087a867e8a773a13df48a627058e1b3 skRm: bdf4e2e587afdf0930644a0c45053889ebcadeca662d7c755a353d5b4e2a8394 ikmS: 6262031f040a9db853edd6f91d2272596eabbc78a2ed2bd643f770ecd0f19b82 pkSm: 049f158c750e55d8d5ad13ede66cf6e79801634b7acadcad72044eac2ae1d04800 69133d6488bf73863fa988c4ba8bde1c2e948b761274802b4d8012af4f13af9e skSm: b0ed8721db6185435898650f7a677affce925aba7975a582653c4cb13c72d240 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 046a1de3fc26a3d43f4e4ba97dbe24f7e99181136129c48fbe872d4743e2b131357 ed4f29a7b317dc22509c7b00991ae990bf65f8b236700c82ab7c11a84511401 shared_secret: d4c27698391db126f1612d9e91a767f10b9b19aa17e1695549203f0df7d9aebe key_schedule_context: 03b873cdf2dff4c1434988053b7a775e980dd2039ea24f950b 26b056ccedcb933198e486f9c9c09c9b5c753ac72d6005de254c607d1b534ed11d493ae1 c1d9ac85 secret: 3bf9d4c7955da2740414e73081fa74d6f6f2b4b9645d0685219813ce99a2f270 key: 4d567121d67fae1227d90e11585988fb base_nonce: 67c9d05330ca21e5116ecda6 exporter_secret: 3f479020ae186788e4dfd4a42a21d24f3faabb224dd4f91c2b2e5e9524ca27b2 Barnes, et al. Expires 27 November 2021 [Page 67] Internet-Draft HPKE May 2021 A.3.4.1. Encryptions sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 67c9d05330ca21e5116ecda6 ct: b9f36d58d9eb101629a3e5a7b63d2ee4af42b3644209ab37e0a272d44365407db8e6 55c72e4fa46f4ff81b9246 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 67c9d05330ca21e5116ecda7 ct: 51788c4e5d56276771032749d015d3eea651af0c7bb8e3da669effffed299ea1f641 df621af65579c10fc09736 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 67c9d05330ca21e5116ecda4 ct: 3b5a2be002e7b29927f06442947e1cf709b9f8508b03823127387223d712703471c2 66efc355f1bc2036f3027c sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 67c9d05330ca21e5116ecda2 ct: 8ddbf1242fe5c7d61e1675496f3bfdb4d90205b3dfbc1b12aab41395d71a82118e09 5c484103107cf4face5123 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 67c9d05330ca21e5116ecd59 ct: 6de25ceadeaec572fbaa25eda2558b73c383fe55106abaec24d518ef6724a7ce698f 83ecdc53e640fe214d2f42 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 67c9d05330ca21e5116ecca6 ct: f380e19d291e12c5e378b51feb5cd50f6d00df6cb2af8393794c4df342126c2e2963 3fe7e8ce49587531affd4d A.3.4.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 68] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 595ce0eff405d4b3bb1d08308d70a4e77226ce11766e0a94c4fdb5d90025c978 exporter_context: 00 L: 32 exported_value: 110472ee0ae328f57ef7332a9886a1992d2c45b9b8d5abc9424ff68630f7d38d exporter_context: 54657374436f6e74657874 L: 32 exported_value: 18ee4d001a9d83a4c67e76f88dd747766576cac438723bad0700a910a4d717e6 A.4. DHKEM(P-256, HKDF-SHA256), HKDF-SHA512, AES-128-GCM A.4.1. Base Setup Information mode: 0 kem_id: 16 kdf_id: 3 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 4ab11a9dd78c39668f7038f921ffc0993b368171d3ddde8031501ee1e08c4c9a pkEm: 0493ed86735bdfb978cc055c98b45695ad7ce61ce748f4dd63c525a3b8d53a1556 5c6897888070070c1579db1f86aaa56deb8297e64db7e8924e72866f9a472580 skEm: 2292bf14bb6e15b8c81a0f45b7a6e93e32d830e48cca702e0affcfb4d07e1b5c ikmR: ea9ff7cc5b2705b188841c7ace169290ff312a9cb31467784ca92d7a2e6e1be8 pkRm: 04085aa5b665dc3826f9650ccbcc471be268c8ada866422f739e2d531d4a8818a9 466bc6b449357096232919ec4fe9070ccbac4aac30f4a1a53efcf7af90610edd skRm: 3ac8530ad1b01885960fab38cf3cdc4f7aef121eaa239f222623614b4079fb38 enc: 0493ed86735bdfb978cc055c98b45695ad7ce61ce748f4dd63c525a3b8d53a15565 c6897888070070c1579db1f86aaa56deb8297e64db7e8924e72866f9a472580 shared_secret: 02f584736390fc93f5b4ad039826a3fa08e9911bd1215a3db8e8791ba533cafd key_schedule_context: 005b8a3617af7789ee716e7911c7e77f84cdc4cc46e60fb7e1 9e4059f9aeadc00585e26874d1ddde76e551a7679cd47168c466f6e1f705cc9374c19277 8a34fcd5ca221d77e229a9d11b654de7942d685069c633b2362ce3b3d8ea4891c9a2a87a 4eb7cdb289ba5e2ecbf8cd2c8498bb4a383dc021454d70d46fcbbad1252ef4f9 secret: 0c7acdab61693f936c4c1256c78e7be30eebfe466812f9cc49f0b58dc970328d fc03ea359be0250a471b1635a193d2dfa8cb23c90aa2e25025b892a725353eeb key: 090ca96e5f8aa02b69fac360da50ddf9 base_nonce: 9c995e621bf9a20c5ca45546 exporter_secret: 4a7abb2ac43e6553f129b2c5750a7e82d149a76ed56dc342d7bca61 e26d494f4855dff0d0165f27ce57756f7f16baca006539bb8e4518987ba610480ac03efa 8 Barnes, et al. Expires 27 November 2021 [Page 69] Internet-Draft HPKE May 2021 A.4.1.1. Encryptions sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 9c995e621bf9a20c5ca45546 ct: d3cf4984931484a080f74c1bb2a6782700dc1fef9abe8442e44a6f09044c88907200 b332003543754eb51917ba sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 9c995e621bf9a20c5ca45547 ct: d14414555a47269dfead9fbf26abb303365e40709a4ed16eaefe1f2070f1ddeb1bdd 94d9e41186f124e0acc62d sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 9c995e621bf9a20c5ca45544 ct: 9bba136cade5c4069707ba91a61932e2cbedda2d9c7bdc33515aa01dd0e0f7e9d357 9bf4016dec37da4aafa800 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 9c995e621bf9a20c5ca45542 ct: a531c0655342be013bf32112951f8df1da643602f1866749519f5dcb09cc68432579 de305a77e6864e862a7600 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 9c995e621bf9a20c5ca455b9 ct: be5da649469efbad0fb950366a82a73fefeda5f652ec7d3731fac6c4ffa21a7004d2 ab8a04e13621bd3629547d sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 9c995e621bf9a20c5ca45446 ct: 62092672f5328a0dde095e57435edf7457ace60b26ee44c9291110ec135cb0e14b85 594e4fea11247d937deb62 A.4.1.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 70] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: a32186b8946f61aeead1c093fe614945f85833b165b28c46bf271abf16b57208 exporter_context: 00 L: 32 exported_value: 84998b304a0ea2f11809398755f0abd5f9d2c141d1822def79dd15c194803c2a exporter_context: 54657374436f6e74657874 L: 32 exported_value: 93fb9411430b2cfa2cf0bed448c46922a5be9beff20e2e621df7e4655852edbc A.4.2. PSK Setup Information mode: 1 kem_id: 16 kdf_id: 3 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: c11d883d6587f911d2ddbc2a0859d5b42fb13bf2c8e89ef408a25564893856f5 pkEm: 04a307934180ad5287f95525fe5bc6244285d7273c15e061f0f2efb211c35057f3 079f6e0abae200992610b25f48b63aacfcb669106ddee8aa023feed301901371 skEm: a5901ff7d6931959c2755382ea40a4869b1dec3694ed3b009dda2d77dd488f18 ikmR: 75bfc2a3a3541170a54c0b06444e358d0ee2b4fb78a401fd399a47a33723b700 pkRm: 043f5266fba0742db649e1043102b8a5afd114465156719cea90373229aabdd84d 7f45dabfc1f55664b888a7e86d594853a6cccdc9b189b57839cbbe3b90b55873 skRm: bc6f0b5e22429e5ff47d5969003f3cae0f4fec50e23602e880038364f33b8522 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 04a307934180ad5287f95525fe5bc6244285d7273c15e061f0f2efb211c35057f30 79f6e0abae200992610b25f48b63aacfcb669106ddee8aa023feed301901371 shared_secret: 2912aacc6eaebd71ff715ea50f6ef3a6637856b2a4c58ea61e0c3fc159e3bc16 key_schedule_context: 01713f73042575cebfd132f0cc4338523f8eae95c80a749f7c f3eb9436ff1c612ca62c37df27ca46d2cc162445a92c5f5fdc57bcde129ca7b1f284b0c1 2297c037ca221d77e229a9d11b654de7942d685069c633b2362ce3b3d8ea4891c9a2a87a 4eb7cdb289ba5e2ecbf8cd2c8498bb4a383dc021454d70d46fcbbad1252ef4f9 secret: ff2051d2128d5f3078de867143e076262ce1d0aecafc3fff3d607f1eaff05345 c7d5ffcb3202cdecb3d1a2f7da20592a237747b6e855390cbe2109d3e6ac70c2 key: 0b910ba8d9cfa17e5f50c211cb32839a base_nonce: 0c29e714eb52de5b7415a1b7 exporter_secret: 50c0a182b6f94b4c0bd955c4aa20df01f282cc12c43065a0812fe4d 4352790171ed2b2c4756ad7f5a730ba336c8f1edd0089d8331192058c385bae39c7cc8b5 7 Barnes, et al. Expires 27 November 2021 [Page 71] Internet-Draft HPKE May 2021 A.4.2.1. Encryptions sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 0c29e714eb52de5b7415a1b7 ct: 57624b6e320d4aba0afd11f548780772932f502e2ba2a8068676b2a0d3b5129a45b9 faa88de39e8306da41d4cc sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 0c29e714eb52de5b7415a1b6 ct: 159d6b4c24bacaf2f5049b7863536d8f3ffede76302dace42080820fa51925d4e1c7 2a64f87b14291a3057e00a sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 0c29e714eb52de5b7415a1b5 ct: bd24140859c99bf0055075e9c460032581dd1726d52cf980d308e9b20083ca62e700 b17892bcf7fa82bac751d0 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 0c29e714eb52de5b7415a1b3 ct: 93ddd55f82e9aaaa3cfc06840575f09d80160b20538125c2549932977d1238dde812 6a4a91118faf8632f62cb8 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 0c29e714eb52de5b7415a148 ct: 377a98a3c34bf716581b05a6b3fdc257f245856384d5f2241c8840571c52f5c85c21 138a4a81655edab8fe227d sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 0c29e714eb52de5b7415a0b7 ct: cc161f5a179831d456d119d2f2c19a6817289c75d1c61cd37ac8a450acd9efba02e0 ac00d128c17855931ff69a A.4.2.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 72] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 8158bea21a6700d37022bb7802866edca30ebf2078273757b656ef7fc2e428cf exporter_context: 00 L: 32 exported_value: 6a348ba6e0e72bb3ef22479214a139ef8dac57be34509a61087a12565473da8d exporter_context: 54657374436f6e74657874 L: 32 exported_value: 2f6d4f7a18ec48de1ef4469f596aada4afdf6d79b037ed3c07e0118f8723bffc A.4.3. Auth Setup Information Barnes, et al. Expires 27 November 2021 [Page 73] Internet-Draft HPKE May 2021 mode: 2 kem_id: 16 kdf_id: 3 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 6bb031aa9197562da0b44e737db2b9e61f6c3ea1138c37de28fc37ac29bc7350 pkEm: 04fec59fa9f76f5d0f6c1660bb179cb314ed97953c53a60ab38f8e6ace60fd5917 8084d0dd66e0f79172992d4ddb2e91172ce24949bcebfff158dcc417f2c6e9c6 skEm: 93cddd5288e7ef4884c8fe321d075df01501b993ff49ffab8184116f39b3c655 ikmR: 649a3f92edbb7a2516a0ade0b7dccc58a37240c4ba06f9726a952227b4adf6ff pkRm: 04378bad519aab406e04d0e5608bcca809c02d6afd2272d4dd03e9357bd0eee8ad f84c8deba3155c9cf9506d1d4c8bfefe3cf033a75716cc3cc07295100ec96276 skRm: 1ea4484be482bf25fdb2ed39e6a02ed9156b3e57dfb18dff82e4a048de990236 ikmS: 4d79b8691aab55a7265e8490a04bb3860ed64dece90953ad0dc43a6ea59b4bf2 pkSm: 0404d3c1f9fca22eb4a6d326125f0814c35593b1da8ea0d11a640730b215a259b9 b98a34ad17e21617d19fe1d4fa39a4828bfdb306b729ec51c543caca3b2d9529 skSm: 02b266d66919f7b08f42ae0e7d97af4ca98b2dae3043bb7e0740ccadc1957579 enc: 04fec59fa9f76f5d0f6c1660bb179cb314ed97953c53a60ab38f8e6ace60fd59178 084d0dd66e0f79172992d4ddb2e91172ce24949bcebfff158dcc417f2c6e9c6 shared_secret: 1ed49f6d7ada333d171cd63861a1cb700a1ec4236755a9cd5f9f8f67a2f8e7b3 key_schedule_context: 025b8a3617af7789ee716e7911c7e77f84cdc4cc46e60fb7e1 9e4059f9aeadc00585e26874d1ddde76e551a7679cd47168c466f6e1f705cc9374c19277 8a34fcd5ca221d77e229a9d11b654de7942d685069c633b2362ce3b3d8ea4891c9a2a87a 4eb7cdb289ba5e2ecbf8cd2c8498bb4a383dc021454d70d46fcbbad1252ef4f9 secret: 9c846ba81ddbbd57bc26d99da6cf7ab956bb735ecd47fe21ed14241c70791b74 84c1d06663d21a5d97bf1be70d56ab727f650c4f859c5ed3f71f8928b3c082dd key: 9d4b1c83129f3de6db95faf3d539dcf1 base_nonce: ea4fd7a485ee5f1f4b62c1b7 exporter_secret: ca2410672369aae1afd6c2639f4fe34ca36d35410c090608d2924f6 0def17f910d7928575434d7f991b1f19d3e8358b8278ff59ced0d5eed4774cec72e12766 e A.4.3.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 74] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: ea4fd7a485ee5f1f4b62c1b7 ct: 2480179d880b5f458154b8bfe3c7e8732332de84aabf06fc440f6b31f169e154157f a9eb44f2fa4d7b38a9236e sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: ea4fd7a485ee5f1f4b62c1b6 ct: 10cd81e3a816d29942b602a92884348171a31cbd0f042c3057c65cd93c540943a5b0 5115bd520c09281061935b sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: ea4fd7a485ee5f1f4b62c1b5 ct: 920743a88d8cf6a09e1a3098e8be8edd09db136e9d543f215924043af8c7410f68ce 6aa64fd2b1a176e7f6b3fd sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: ea4fd7a485ee5f1f4b62c1b3 ct: 6b11380fcc708fc8589effb5b5e0394cbd441fa5e240b5500522150ca8265d65ff55 479405af936e2349119dcd sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: ea4fd7a485ee5f1f4b62c148 ct: d084eca50e7554bb97ba34c4482dfe32c9a2b7f3ab009c2d1b68ecbf97bee2d28cd9 4b6c829b96361f2701772d sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: ea4fd7a485ee5f1f4b62c0b7 ct: 247da592cc4ce834a94de2c79f5730ee49342470a021e4a4bc2bb77c53b17413e94d 94f57b4fdaedcf97cfe7b1 A.4.3.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 75] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: f03fbc82f321a0ab4840e487cb75d07aafd8e6f68485e4f7ff72b2f55ff24ad6 exporter_context: 00 L: 32 exported_value: 1ce0cadec0a8f060f4b5070c8f8888dcdfefc2e35819df0cd559928a11ff0891 exporter_context: 54657374436f6e74657874 L: 32 exported_value: 70c405c707102fd0041ea716090753be47d68d238b111d542846bd0d84ba907c A.4.4. AuthPSK Setup Information Barnes, et al. Expires 27 November 2021 [Page 76] Internet-Draft HPKE May 2021 mode: 3 kem_id: 16 kdf_id: 3 aead_id: 1 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 37ae06a521cd555648c928d7af58ad2aa4a85e34b8cabd069e94ad55ab872cc8 pkEm: 04801740f4b1b35823f7fb2930eac2efc8c4893f34ba111c0bb976e3c7d5dc0aef 5a7ef0bf4057949a140285f774f1efc53b3860936b92279a11b68395d898d138 skEm: 778f2254ae5d661d5c7fca8c4a7495a25bd13f26258e459159f3899df0de76c1 ikmR: 7466024b7e2d2366c3914d7833718f13afb9e3e45bcfbb510594d614ddd9b4e7 pkRm: 04a4ca7af2fc2cce48edbf2f1700983e927743a4e85bb5035ad562043e25d9a111 cbf6f7385fac55edc5c9d2ca6ed351a5643de95c36748e11dbec98730f4d43e9 skRm: 00510a70fde67af487c093234fc4215c1cdec09579c4b30cc8e48cb530414d0e ikmS: ee27aaf99bf5cd8398e9de88ac09a82ac22cdb8d0905ab05c0f5fa12ba1709f3 pkSm: 04b59a4157a9720eb749c95f842a5e3e8acdccbe834426d405509ac3191e23f216 5b5bb1f07a6240dd567703ae75e13182ee0f69fc102145cdb5abf681ff126d60 skSm: d743b20821e6326f7a26684a4beed7088b35e392114480ca9f6c325079dcf10b psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 04801740f4b1b35823f7fb2930eac2efc8c4893f34ba111c0bb976e3c7d5dc0aef5 a7ef0bf4057949a140285f774f1efc53b3860936b92279a11b68395d898d138 shared_secret: 02bee8be0dda755846115db45071c0cf59c25722e015bde1c124de849c0fea52 key_schedule_context: 03713f73042575cebfd132f0cc4338523f8eae95c80a749f7c f3eb9436ff1c612ca62c37df27ca46d2cc162445a92c5f5fdc57bcde129ca7b1f284b0c1 2297c037ca221d77e229a9d11b654de7942d685069c633b2362ce3b3d8ea4891c9a2a87a 4eb7cdb289ba5e2ecbf8cd2c8498bb4a383dc021454d70d46fcbbad1252ef4f9 secret: 0f9df08908a6a3d06c8e934cd3f5313f9ebccd0986e316c0198bb48bed30dc3d b2f3baab94fd40c2c285c7288c77e2255401ee2d5884306addf4296b93c238b3 key: b68bb0e2fbf7431cedb46cc3b6f1fe9e base_nonce: 76af62719d33d39a1cb6be9f exporter_secret: 7f72308ae68c9a2b3862e686cb547b16d33d00fe482c770c4717d8b 54e9b1e547244c3602bdd86d5a788a8443befea0a7658002b23f1c96a62a64986fffc511 a A.4.4.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 77] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 76af62719d33d39a1cb6be9f ct: 840669634db51e28df54f189329c1b727fd303ae413f003020aff5e26276aaa910fc 4296828cb9d862c2fd7d16 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 76af62719d33d39a1cb6be9e ct: d4680a48158d9a75fd09355878d6e33997a36ee01d4a8f22032b22373b795a941b7b 9c5205ff99e0ff284beef4 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 76af62719d33d39a1cb6be9d ct: c45eb6597de2bac929a0f5d404ba9d2dc1ea031880930f1fd7a283f0a0cbebb35eac 1a9ee0d1225f5e0f181571 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 76af62719d33d39a1cb6be9b ct: 4ee2482ad8d7d1e9b7e651c78b6ca26d3c5314d0711710ca62c2fd8bb8996d7d8727 c157538d5493da696b61f8 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 76af62719d33d39a1cb6be60 ct: 65596b731df010c76a915c6271a438056ce65696459432eeafdae7b4cadb6290dd61 e68edd4e40b659d2a8cbcc sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 76af62719d33d39a1cb6bf9f ct: 9f659482ebc52f8303f9eac75656d807ec38ce2e50c72e3078cd13d86b30e3f89069 0a873277620f8a6a42d836 A.4.4.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 78] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: c8c917e137a616d3d4e4c9fcd9c50202f366cb0d37862376bc79f9b72e8a8db9 exporter_context: 00 L: 32 exported_value: 33a5d4df232777008a06d0684f23bb891cfaef702f653c8601b6ad4d08dddddf exporter_context: 54657374436f6e74657874 L: 32 exported_value: bed80f2e54f1285895c4a3f3b3625e6206f78f1ed329a0cfb5864f7c139b3c6a A.5. DHKEM(P-256, HKDF-SHA256), HKDF-SHA256, ChaCha20Poly1305 A.5.1. Base Setup Information mode: 0 kem_id: 16 kdf_id: 1 aead_id: 3 info: 4f6465206f6e2061204772656369616e2055726e ikmE: f1f1a3bc95416871539ecb51c3a8f0cf608afb40fbbe305c0a72819d35c33f1f pkEm: 04c07836a0206e04e31d8ae99bfd549380b072a1b1b82e563c935c095827824fc1 559eac6fb9e3c70cd3193968994e7fe9781aa103f5b50e934b5b2f387e381291 skEm: 7550253e1147aae48839c1f8af80d2770fb7a4c763afe7d0afa7e0f42a5b3689 ikmR: 61092f3f56994dd424405899154a9918353e3e008171517ad576b900ddb275e7 pkRm: 04a697bffde9405c992883c5c439d6cc358170b51af72812333b015621dc0f40ba d9bb726f68a5c013806a790ec716ab8669f84f6b694596c2987cf35baba2a006 skRm: a4d1c55836aa30f9b3fbb6ac98d338c877c2867dd3a77396d13f68d3ab150d3b enc: 04c07836a0206e04e31d8ae99bfd549380b072a1b1b82e563c935c095827824fc15 59eac6fb9e3c70cd3193968994e7fe9781aa103f5b50e934b5b2f387e381291 shared_secret: 806520f82ef0b03c823b7fc524b6b55a088f566b9751b89551c170f4113bd850 key_schedule_context: 00b738cd703db7b4106e93b4621e9a19c89c838e55964240e5 d3f331aaf8b0d58b2e986ea1c671b61cf45eec134dac0bae58ec6f63e790b1400b47c330 38b0269c secret: fe891101629aa355aad68eff3cc5170d057eca0c7573f6575e91f9783e1d4506 key: a8f45490a92a3b04d1dbf6cf2c3939ad8bfc9bfcb97c04bffe116730c9dfe3fc base_nonce: 726b4390ed2209809f58c693 exporter_secret: 4f9bd9b3a8db7d7c3a5b9d44fdc1f6e37d5d77689ade5ec44a7242016e6aa205 A.5.1.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 79] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 726b4390ed2209809f58c693 ct: 6469c41c5c81d3aa85432531ecf6460ec945bde1eb428cb2fedf7a29f5a685b4ccb0 d057f03ea2952a27bb458b sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 726b4390ed2209809f58c692 ct: f1564199f7e0e110ec9c1bcdde332177fc35c1adf6e57f8d1df24022227ffa871686 2dbda2b1dc546c9d114374 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 726b4390ed2209809f58c691 ct: 39de89728bcb774269f882af8dc5369e4f3d6322d986e872b3a8d074c7c18e8549ff 3f85b6d6592ff87c3f310c sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 726b4390ed2209809f58c697 ct: bc104a14fbede0cc79eeb826ea0476ce87b9c928c36e5e34dc9b6905d91473ec369a 08b1a25d305dd45c6c5f80 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 726b4390ed2209809f58c66c ct: 8f2814a2c548b3be50259713c6724009e092d37789f6856553d61df23ebc079235f7 10e6af3c3ca6eaba7c7c6c sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 726b4390ed2209809f58c793 ct: b45b69d419a9be7219d8c94365b89ad6951caf4576ea4774ea40e9b7047a09d6537d 1aa2f7c12d6ae4b729b4d0 A.5.1.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 80] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 9b13c510416ac977b553bf1741018809c246a695f45eff6d3b0356dbefe1e660 exporter_context: 00 L: 32 exported_value: 6c8b7be3a20a5684edecb4253619d9051ce8583baf850e0cb53c402bdcaf8ebb exporter_context: 54657374436f6e74657874 L: 32 exported_value: 477a50d804c7c51941f69b8e32fe8288386ee1a84905fe4938d58972f24ac938 A.5.2. PSK Setup Information mode: 1 kem_id: 16 kdf_id: 1 aead_id: 3 info: 4f6465206f6e2061204772656369616e2055726e ikmE: e1a4e1d50c4bfcf890f2b4c7d6b2d2aca61368eddc3c84162df2856843e1057a pkEm: 04f336578b72ad7932fe867cc4d2d44a718a318037a0ec271163699cee653fa805 c1fec955e562663e0c2061bb96a87d78892bff0cc0bad7906c2d998ebe1a7246 skEm: 7d6e4e006cee68af9b3fdd583a0ee8962df9d59fab029997ee3f456cbc857904 ikmR: ee51dec304abf993ef8fd52aacdd3b539108bbf6e491943266c1de89ec596a17 pkRm: 041eb8f4f20ab72661af369ff3231a733672fa26f385ffb959fd1bae46bfda43ad 55e2d573b880831381d9367417f554ce5b2134fbba5235b44db465feffc6189e skRm: 12ecde2c8bc2d5d7ed2219c71f27e3943d92b344174436af833337c557c300b3 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 04f336578b72ad7932fe867cc4d2d44a718a318037a0ec271163699cee653fa805c 1fec955e562663e0c2061bb96a87d78892bff0cc0bad7906c2d998ebe1a7246 shared_secret: ac4f260dce4db6bf45435d9c92c0e11cfdd93743bd3075949975974cc2b3d79e key_schedule_context: 01622b72afcc3795841596c67ea74400ca3b029374d7d5640b da367c5d67b3fbeb2e986ea1c671b61cf45eec134dac0bae58ec6f63e790b1400b47c330 38b0269c secret: 858c8087a1c056db5811e85802f375bb0c19b9983204a1575de4803575d23239 key: 6d61cb330b7771168c8619498e753f16198aad9566d1f1c6c70e2bc1a1a8b142 base_nonce: 0de7655fb65e1cd51a38864e exporter_secret: 754ca00235b245e72d1f722a7718e7145bd113050a2aa3d89586d4cb7514bfdb A.5.2.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 81] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 0de7655fb65e1cd51a38864e ct: 21433eaff24d7706f3ed5b9b2e709b07230e2b11df1f2b1fe07b3c70d5948a53d6fa 5c8bed194020bd9df0877b sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 0de7655fb65e1cd51a38864f ct: c74a764b4892072ea8c2c56b9bcd46c7f1e9ca8cb0a263f8b40c2ba59ac9c857033f 176019562218769d3e0452 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 0de7655fb65e1cd51a38864c ct: dc8cd68863474d6e9cbb6a659335a86a54e036249d41acf909e738c847ff2bd36fe3 fcacda4ededa7032c0a220 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 0de7655fb65e1cd51a38864a ct: cd54a8576353b1b9df366cb0cc042e46eef6f4cf01e205fe7d47e306b2fdd90f7185 f289a26c613ca094e3be10 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 0de7655fb65e1cd51a3886b1 ct: 6324570c9d542c70c7e70570c1d8f4c52a89484746bf0625441890ededcc80c24ef2 301c38bfd34d689d19f67d sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 0de7655fb65e1cd51a38874e ct: 1ea6326c8098ed0437a553c466550114fb2ca1412cca7de98709b9ccdf19206e52c3 d39180e2cf62b3e9f4baf4 A.5.2.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 82] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 530bbc2f68f078dccc89cc371b4f4ade372c9472bafe4601a8432cbb934f528d exporter_context: 00 L: 32 exported_value: 6e25075ddcc528c90ef9218f800ca3dfe1b8ff4042de5033133adb8bd54c401d exporter_context: 54657374436f6e74657874 L: 32 exported_value: 6f6fbd0d1c7733f796461b3235a856cc34f676fe61ed509dfc18fa16efe6be78 A.5.3. Auth Setup Information mode: 2 kem_id: 16 kdf_id: 1 aead_id: 3 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 0ecd212019008138a31f9104d5dba76b9f8e34d5b996041fff9e3df221dd0d5d pkEm: 040d5176aedba55bc41709261e9195c5146bb62d783031280775f32e507d79b5cb c5748b6be6359760c73cfe10ca19521af704ca6d91ff32fc0739527b9385d415 skEm: 085fd5d5e6ce6497c79df960cac93710006b76217d8bcfafbd2bb2c20ea03c42 ikmR: d32236d8378b9563840653789eb7bc33c3c720e537391727bf1c812d0eac110f pkRm: 0444f6ee41818d9fe0f8265bffd016b7e2dd3964d610d0f7514244a60dbb7a11ec e876bb110a97a2ac6a9542d7344bf7d2bd59345e3e75e497f7416cf38d296233 skRm: 3cb2c125b8c5a81d165a333048f5dcae29a2ab2072625adad66dbb0f48689af9 ikmS: 0e6be0851283f9327295fd49858a8c8908ea9783212945eef6c598ee0a3cedbb pkSm: 04265529a04d4f46ab6fa3af4943774a9f1127821656a75a35fade898a9a1b014f 64d874e88cddb24c1c3d79004d3a587db67670ca357ff4fba7e8b56ec013b98b skSm: 39b19402e742d48d319d24d68e494daa4492817342e593285944830320912519 enc: 040d5176aedba55bc41709261e9195c5146bb62d783031280775f32e507d79b5cbc 5748b6be6359760c73cfe10ca19521af704ca6d91ff32fc0739527b9385d415 shared_secret: 1a45aa4792f4b166bfee7eeab0096c1a6e497480e2261b2a59aad12f2768d469 key_schedule_context: 02b738cd703db7b4106e93b4621e9a19c89c838e55964240e5 d3f331aaf8b0d58b2e986ea1c671b61cf45eec134dac0bae58ec6f63e790b1400b47c330 38b0269c secret: 9193210815b87a4c5496c9d73e609a6c92665b5ea0d760866294906d089ebb57 key: cf292f8a4313280a462ce55cde05b5aa5744fe4ca89a5d81b0146a5eaca8092d base_nonce: 7e45c21e20e869ae00492123 exporter_secret: dba6e307f71769ba11e2c687cc19592f9d436da0c81e772d7a8a9fd28e54355f Barnes, et al. Expires 27 November 2021 [Page 83] Internet-Draft HPKE May 2021 A.5.3.1. Encryptions sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 7e45c21e20e869ae00492123 ct: 25881f219935eec5ba70d7b421f13c35005734f3e4d959680270f55d71e2f5cb3bd2 daced2770bf3d9d4916872 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 7e45c21e20e869ae00492122 ct: 653f0036e52a376f5d2dd85b3204b55455b7835c231255ae098d09ed138719b97185 129786338ab6543f753193 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 7e45c21e20e869ae00492121 ct: 60878706117f22180c788e62df6a595bc41906096a11a9513e84f0141e43239e81a9 8d7a235abc64112fcb8ddd sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 7e45c21e20e869ae00492127 ct: 0f9094dd08240b5fa7a388b824d19d5b4b1e126cebfd67a062c32f9ba9f1f3866cc3 8de7df2702626e2ab65c0f sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 7e45c21e20e869ae004921dc ct: dd29319e08135c5f8401d6537a364e92172c0e3f095f3fd18923881d11c0a6839345 dd0b54acd0edd8f8344792 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 7e45c21e20e869ae00492023 ct: e2276ec5047bc4b6ed57d6da7da2fb47a77502f0a30f17d040247c73da336d722bc6 c89adf68396a0912c6d152 A.5.3.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 84] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 56c4d6c1d3a46c70fd8f4ecda5d27c70886e348efb51bd5edeaa39ff6ce34389 exporter_context: 00 L: 32 exported_value: d2d3e48ed76832b6b3f28fa84be5f11f09533c0e3c71825a34fb0f1320891b51 exporter_context: 54657374436f6e74657874 L: 32 exported_value: eb0d312b6263995b4c7761e64b688c215ffd6043ff3bad2368c862784cbe6eff A.5.4. AuthPSK Setup Information mode: 3 kem_id: 16 kdf_id: 1 aead_id: 3 info: 4f6465206f6e2061204772656369616e2055726e ikmE: f3a07f194703e321ef1f753a1b9fe27a498dfdfa309151d70bedd896c239c499 pkEm: 043539917ee26f8ae0aa5f784a387981b13de33124a3cde88b94672030183110f3 31400115855808244ff0c5b6ca6104483ac95724481d41bdcd9f15b430ad16f6 skEm: 11b7e4de2d919240616a31ab14944cced79bc2372108bb98f6792e3b645fe546 ikmR: 1240e55a0a03548d7f963ef783b6a7362cb505e6b31dfd04c81d9b294543bfbd pkRm: 04d383fd920c42d018b9d57fd73a01f1eee480008923f67d35169478e55d2e8817 068daf62a06b10e0aad4a9e429fa7f904481be96b79a9c231a33e956c20b81b6 skRm: c29fc577b7e74d525c0043f1c27540a1248e4f2c8d297298e99010a92e94865c ikmS: ce2a0387a2eb8870a3a92c34a2975f0f3f271af4384d446c7dc1524a6c6c515a pkSm: 0492cf8c9b144b742fe5a63d9a181a19d416f3ec8705f24308ad316564823c344e 018bd7c03a33c926bb271b28ef5bf28c0ca00abff249fee5ef7f33315ff34fdb skSm: 53541bd995f874a67f8bfd8038afa67fd68876801f42ff47d0dc2a4deea067ae psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 043539917ee26f8ae0aa5f784a387981b13de33124a3cde88b94672030183110f33 1400115855808244ff0c5b6ca6104483ac95724481d41bdcd9f15b430ad16f6 shared_secret: 87584311791036a3019bc36803cdd42e9a8931a98b13c88835f2f8a9036a4fd6 key_schedule_context: 03622b72afcc3795841596c67ea74400ca3b029374d7d5640b da367c5d67b3fbeb2e986ea1c671b61cf45eec134dac0bae58ec6f63e790b1400b47c330 38b0269c secret: fe52b4412590e825ea2603fa88e145b2ee014b942a774b55fab4f081301f16f4 key: 31e140c8856941315d4067239fdc4ebe077fbf45a6fc78a61e7a6c8b3bacb10a base_nonce: 75838a8010d2e4760254dd56 exporter_secret: 600895965755db9c5027f25f039a6e3e506c35b3b7084ce33c4a48d59ee1f0e3 Barnes, et al. Expires 27 November 2021 [Page 85] Internet-Draft HPKE May 2021 A.5.4.1. Encryptions sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 75838a8010d2e4760254dd56 ct: 9eadfa0f954835e7e920ffe56dec6b31a046271cf71fdda55db72926e1d8fae94cc6 280fcfabd8db71eaa65c05 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 75838a8010d2e4760254dd57 ct: e357ad10d75240224d4095c9f6150a2ed2179c0f878e4f2db8ca95d365d174d059ff 8c3eb38ea9a65cfc8eaeb8 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 75838a8010d2e4760254dd54 ct: 2fa56d00f8dd479d67a2ec3308325cf3bbccaf102a64ffccdb006bd7dcb932685b9a 7b49cdc094a85fec1da5ef sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 75838a8010d2e4760254dd52 ct: 1fe9d6db14965003ed81a39abf240f9cd7c5a454bca0d69ef9a2de16d537364fbbf1 10b9ef11fa4a7a0172f0ce sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 75838a8010d2e4760254dda9 ct: eaf4041a5c9122b22d1f8d698eeffe45d64b4ae33d0ddca3a4cdf4a5f595acc95a1a 9334d06cc4d000df6aaad6 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 75838a8010d2e4760254dc56 ct: fb857f4185ce5286c1a52431867537204963ea66a3eee8d2a74419fd8751faee066d 08277ac7880473aa4143ba A.5.4.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 86] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: c52b4592cd33dd38b2a3613108ddda28dcf7f03d30f2a09703f758bfa8029c9a exporter_context: 00 L: 32 exported_value: 2f03bebc577e5729e148554991787222b5c2a02b77e9b1ac380541f710e5a318 exporter_context: 54657374436f6e74657874 L: 32 exported_value: e01dd49e8bfc3d9216abc1be832f0418adf8b47a7b5a330a7436c31e33d765d7 A.6. DHKEM(P-521, HKDF-SHA512), HKDF-SHA512, AES-256-GCM A.6.1. Base Setup Information Barnes, et al. Expires 27 November 2021 [Page 87] Internet-Draft HPKE May 2021 mode: 0 kem_id: 18 kdf_id: 3 aead_id: 2 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 7f06ab8215105fc46aceeb2e3dc5028b44364f960426eb0d8e4026c2f8b5d7e7a9 86688f1591abf5ab753c357a5d6f0440414b4ed4ede71317772ac98d9239f70904 pkEm: 040138b385ca16bb0d5fa0c0665fbbd7e69e3ee29f63991d3e9b5fa740aab8900a aeed46ed73a49055758425a0ce36507c54b29cc5b85a5cee6bae0cf1c21f2731ece2013d c3fb7c8d21654bb161b463962ca19e8c654ff24c94dd2898de12051f1ed0692237fb02b2 f8d1dc1c73e9b366b529eb436e98a996ee522aef863dd5739d2f29b0 skEm: 014784c692da35df6ecde98ee43ac425dbdd0969c0c72b42f2e708ab9d535415a8 569bdacfcc0a114c85b8e3f26acf4d68115f8c91a66178cdbd03b7bcc5291e374b ikmR: 2ad954bbe39b7122529f7dde780bff626cd97f850d0784a432784e69d86eccaade 43b6c10a8ffdb94bf943c6da479db137914ec835a7e715e36e45e29b587bab3bf1 pkRm: 0401b45498c1714e2dce167d3caf162e45e0642afc7ed435df7902ccae0e84ba0f 7d373f646b7738bbbdca11ed91bdeae3cdcba3301f2457be452f271fa6837580e661012a f49583a62e48d44bed350c7118c0d8dc861c238c72a2bda17f64704f464b57338e7f40b6 0959480c0e58e6559b190d81663ed816e523b6b6a418f66d2451ec64 skRm: 01462680369ae375e4b3791070a7458ed527842f6a98a79ff5e0d4cbde83c27196 a3916956655523a6a2556a7af62c5cadabe2ef9da3760bb21e005202f7b2462847 enc: 040138b385ca16bb0d5fa0c0665fbbd7e69e3ee29f63991d3e9b5fa740aab8900aa eed46ed73a49055758425a0ce36507c54b29cc5b85a5cee6bae0cf1c21f2731ece2013dc 3fb7c8d21654bb161b463962ca19e8c654ff24c94dd2898de12051f1ed0692237fb02b2f 8d1dc1c73e9b366b529eb436e98a996ee522aef863dd5739d2f29b0 shared_secret: 776ab421302f6eff7d7cb5cb1adaea0cd50872c71c2d63c30c4f1d5e4 3653336fef33b103c67e7a98add2d3b66e2fda95b5b2a667aa9dac7e59cc1d46d30e818 key_schedule_context: 0083a27c5b2358ab4dae1b2f5d8f57f10ccccc822a473326f5 43f239a70aee46347324e84e02d7651a10d08fb3dda739d22d50c53fbfa8122baacd0f9a e5913072ef45baa1f3a4b169e141feb957e48d03f28c837d8904c3d6775308c3d3faa75d d64adfa44e1a1141edf9349959b8f8e5291cbdc56f62b0ed6527d692e85b09a4 secret: 49fd9f53b0f93732555b2054edfdc0e3101000d75df714b98ce5aa295a37f1b1 8dfa86a1c37286d805d3ea09a20b72f93c21e83955a1f01eb7c5eead563d21e7 key: 751e346ce8f0ddb2305c8a2a85c70d5cf559c53093656be636b9406d4d7d1b70 base_nonce: 55ff7a7d739c69f44b25447b exporter_secret: e4ff9dfbc732a2b9c75823763c5ccc954a2c0648fc6de80a5858125 2d0ee3215388a4455e69086b50b87eb28c169a52f42e71de4ca61c920e7bd24c95cc3f99 2 A.6.1.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 88] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 55ff7a7d739c69f44b25447b ct: 170f8beddfe949b75ef9c387e201baf4132fa7374593dfafa90768788b7b2b200aaf cc6d80ea4c795a7c5b841a sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 55ff7a7d739c69f44b25447a ct: d9ee248e220ca24ac00bbbe7e221a832e4f7fa64c4fbab3945b6f3af0c5ecd5e1681 5b328be4954a05fd352256 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 55ff7a7d739c69f44b254479 ct: 142cf1e02d1f58d9285f2af7dcfa44f7c3f2d15c73d460c48c6e0e506a3144bae352 84e7e221105b61d24e1c7a sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 55ff7a7d739c69f44b25447f ct: 3bb3a5a07100e5a12805327bf3b152df728b1c1be75a9fd2cb2bf5eac0cca1fb80ad db37eb2a32938c7268e3e5 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 55ff7a7d739c69f44b254484 ct: 4f268d0930f8d50b8fd9d0f26657ba25b5cb08b308c92e33382f369c768b558e113a c95a4c70dd60909ad1adc7 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 55ff7a7d739c69f44b25457b ct: dbbfc44ae037864e75f136e8b4b4123351d480e6619ae0e0ae437f036f2f8f1ef677 686323977a1ccbb4b4f16a A.6.1.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 89] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 05e2e5bd9f0c30832b80a279ff211cc65eceb0d97001524085d609ead60d0412 exporter_context: 00 L: 32 exported_value: fca69744bb537f5b7a1596dbf34eaa8d84bf2e3ee7f1a155d41bd3624aa92b63 exporter_context: 54657374436f6e74657874 L: 32 exported_value: f389beaac6fcf6c0d9376e20f97e364f0609a88f1bc76d7328e9104df8477013 A.6.2. PSK Setup Information Barnes, et al. Expires 27 November 2021 [Page 90] Internet-Draft HPKE May 2021 mode: 1 kem_id: 18 kdf_id: 3 aead_id: 2 info: 4f6465206f6e2061204772656369616e2055726e ikmE: f3ebfa9a69a924e672114fcd9e06fa9559e937f7eccce4181a2b506df53dbe514b e12f094bb28e01de19dd345b4f7ede5ad7eaa6b9c3019592ec68eaae9a14732ce0 pkEm: 040085eff0835cc84351f32471d32aa453cdc1f6418eaaecf1c2824210eb1d48d0 768b368110fab21407c324b8bb4bec63f042cfa4d0868d19b760eb4beba1bff793b30036 d2c614d55730bd2a40c718f9466faf4d5f8170d22b6df98dfe0c067d02b349ae4a142e0c 03418f0a1479ff78a3db07ae2c2e89e5840f712c174ba2118e90fdcb skEm: 012e5cfe0daf5fe2a1cd617f4c4bae7c86f1f527b3207f115e262a98cc65268ec8 8cb8645aec73b7aa0a472d0292502d1078e762646e0c093cf873243d12c39915f6 ikmR: a2a2458705e278e574f835effecd18232f8a4c459e7550a09d44348ae5d3b1ea9d 95c51995e657ad6f7cae659f5e186126a471c017f8f5e41da9eba74d4e0473e179 pkRm: 04006917e049a2be7e1482759fb067ddb94e9c4f7f5976f655088dec45246614ff 924ed3b385fc2986c0ecc39d14f907bf837d7306aada59dd5889086125ecd038ead40060 3394b5d81f89ebfd556a898cc1d6a027e143d199d3db845cb91c5289fb26c5ff80832935 b0e8dd08d37c6185a6f77683347e472d1edb6daa6bd7652fea628fae skRm: 011bafd9c7a52e3e71afbdab0d2f31b03d998a0dc875dd7555c63560e142bde264 428de03379863b4ec6138f813fa009927dc5d15f62314c56d4e7ff2b485753eb72 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 040085eff0835cc84351f32471d32aa453cdc1f6418eaaecf1c2824210eb1d48d07 68b368110fab21407c324b8bb4bec63f042cfa4d0868d19b760eb4beba1bff793b30036d 2c614d55730bd2a40c718f9466faf4d5f8170d22b6df98dfe0c067d02b349ae4a142e0c0 3418f0a1479ff78a3db07ae2c2e89e5840f712c174ba2118e90fdcb shared_secret: 0d52de997fdaa4797720e8b1bebd3df3d03c4cf38cc8c1398168d36c3 fc7626428c9c254dd3f9274450909c64a5b3acbe45e2d850a2fd69ac0605fe5c8a057a5 key_schedule_context: 0124497637cf18d6fbcc16e9f652f00244c981726f293bb781 9861e85e50c94f0be30e022ab081e18e6f299fd3d3d976a4bc590f85bc7711bfce32ee1a 7fb1c154ef45baa1f3a4b169e141feb957e48d03f28c837d8904c3d6775308c3d3faa75d d64adfa44e1a1141edf9349959b8f8e5291cbdc56f62b0ed6527d692e85b09a4 secret: 2cf425e26f65526afc0634a3dba4e28d980c1015130ce07c2ac7530d7a391a75 e5a0db428b09f27ad4d975b4ad1e7f85800e03ffeea35e8cf3fe67b18d4a1345 key: f764a5a4b17e5d1ffba6e699d65560497ebaea6eb0b0d9010a6d979e298a39ff base_nonce: 479afdf3546ddba3a9841f38 exporter_secret: 5c3d4b65a13570502b93095ef196c42c8211a4a188c4590d3586366 5c705bb140ecba6ce9256be3fad35b4378d41643867454612adfd0542a684b61799bf293 f A.6.2.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 91] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 479afdf3546ddba3a9841f38 ct: de69e9d943a5d0b70be3359a19f317bd9aca4a2ebb4332a39bcdfc97d5fe62f3a777 02f4822c3be531aa7843a1 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 479afdf3546ddba3a9841f39 ct: 77a16162831f90de350fea9152cfc685ecfa10acb4f7994f41aed43fa5431f2382d0 78ec88baec53943984553e sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 479afdf3546ddba3a9841f3a ct: f1d48d09f126b9003b4c7d3fe6779c7c92173188a2bb7465ba43d899a6398a333914 d2bb19fd769d53f3ec7336 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 479afdf3546ddba3a9841f3c ct: 829b11c082b0178082cd595be6d73742a4721b9ac05f8d2ef8a7704a53022d82bd0d 8571f578c5c13b99eccff8 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 479afdf3546ddba3a9841fc7 ct: a3ee291e20f37021e82df14d41f3fbe98b27c43b318a36cacd8471a3b1051ab12ee0 55b62ded95b72a63199a3f sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 479afdf3546ddba3a9841e38 ct: eecc2173ce1ac14b27ee67041e90ed50b7809926e55861a579949c07f6d26137bf9c f0d097f60b5fd2fbf348ec A.6.2.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 92] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 62691f0f971e34de38370bff24deb5a7d40ab628093d304be60946afcdb3a936 exporter_context: 00 L: 32 exported_value: 76083c6d1b6809da088584674327b39488eaf665f0731151128452e04ce81bff exporter_context: 54657374436f6e74657874 L: 32 exported_value: 0c7cfc0976e25ae7680cf909ae2de1859cd9b679610a14bec40d69b91785b2f6 A.6.3. Auth Setup Information Barnes, et al. Expires 27 November 2021 [Page 93] Internet-Draft HPKE May 2021 mode: 2 kem_id: 18 kdf_id: 3 aead_id: 2 info: 4f6465206f6e2061204772656369616e2055726e ikmE: fe1c589c2a05893895a537f38c7cb4300b5a7e8fef3d6ccb8f07a498029c61e902 62e009dc254c7f6235f9c6b2fd6aeff0a714db131b09258c16e217b7bd2aa619b0 pkEm: 04017de12ede7f72cb101dab36a111265c97b3654816dcd6183f809d4b3d111fe7 59497f8aefdc5dbb40d3e6d21db15bdc60f15f2a420761bcaeef73b891c2b117e9cf01e2 9320b799bbc86afdc5ea97d941ea1c5bd5ebeeac7a784b3bab524746f3e640ec26ee1bd9 1255f9330d974f845084637ee0e6fe9f505c5b87c86a4e1a6c3096dd skEm: 0185f03560de87bb2c543ef03607f3c33ac09980000de25eabe3b224312946330d 2e65d192d3b4aa46ca92fc5ca50736b624402d95f6a80dc04d1f10ae9517137261 ikmR: 8feea0438481fc0ecd470d6adfcda334a759c6b8650452c5a5dd9b2dd2cc9be33d 2bb7ee64605fc07ab4664a58bb9a8de80defe510b6c97d2daf85b92cd4bb0a66bf pkRm: 04007d419b8834e7513d0e7cc66424a136ec5e11395ab353da324e3586673ee73d 53ab34f30a0b42a92d054d0db321b80f6217e655e304f72793767c4231785c4a4a6e008f 31b93b7a4f2b8cd12e5fe5a0523dc71353c66cbdad51c86b9e0bdfcd9a45698f2dab1809 ab1b0f88f54227232c858accc44d9a8d41775ac026341564a2d749f4 skRm: 013ef326940998544a899e15e1726548ff43bbdb23a8587aa3bef9d1b857338d87 287df5667037b519d6a14661e9503cfc95a154d93566d8c84e95ce93ad05293a0b ikmS: 2f66a68b85ef04822b054ef521838c00c64f8b6226935593b69e13a1a2461a4f1a 74c10c836e87eed150c0db85d4e4f506cbb746149befac6f5c07dc48a615ef92db pkSm: 04015cc3636632ea9a3879e43240beae5d15a44fba819282fac26a19c989fafdd0 f330b8521dff7dc393101b018c1e65b07be9f5fc9a28a1f450d6a541ee0d76221133001e 8f0f6a05ab79f9b9bb9ccce142a453d59c5abebb5674839d935a3ca1a3fbc328539a60b3 bc3c05fed22838584a726b9c176796cad0169ba4093332cbd2dc3a9f skSm: 001018584599625ff9953b9305849850d5e34bd789d4b81101139662fbea8b6508 ddb9d019b0d692e737f66beae3f1f783e744202aaf6fea01506c27287e359fe776 enc: 04017de12ede7f72cb101dab36a111265c97b3654816dcd6183f809d4b3d111fe75 9497f8aefdc5dbb40d3e6d21db15bdc60f15f2a420761bcaeef73b891c2b117e9cf01e29 320b799bbc86afdc5ea97d941ea1c5bd5ebeeac7a784b3bab524746f3e640ec26ee1bd91 255f9330d974f845084637ee0e6fe9f505c5b87c86a4e1a6c3096dd shared_secret: 26648fa2a2deb0bfc56349a590fd4cb7108a51797b634694fc02061e8 d91b3576ac736a68bf848fe2a58dfb1956d266e68209a4d631e513badf8f4dcfc00f30a key_schedule_context: 0283a27c5b2358ab4dae1b2f5d8f57f10ccccc822a473326f5 43f239a70aee46347324e84e02d7651a10d08fb3dda739d22d50c53fbfa8122baacd0f9a e5913072ef45baa1f3a4b169e141feb957e48d03f28c837d8904c3d6775308c3d3faa75d d64adfa44e1a1141edf9349959b8f8e5291cbdc56f62b0ed6527d692e85b09a4 secret: 56b7acb7355d080922d2ddc227829c2276a0b456087654b3ac4b53828bd34af8 cf54626f85af858a15a86eba73011665cc922bc59fd07d2975f356d2674db554 key: 01fced239845e53f0ec616e71777883a1f9fcab22a50f701bdeee17ad040e44d base_nonce: 9752b85fe8c73eda183f9e80 exporter_secret: 80466a9d9cc5112ddad297e817e038801e15fa18152bc4dc010a35d 7f534089c87c98b4bacd7bbc6276c4002a74085adcd9019fca6139826b5292569cfb7fe4 7 Barnes, et al. Expires 27 November 2021 [Page 94] Internet-Draft HPKE May 2021 A.6.3.1. Encryptions sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: 9752b85fe8c73eda183f9e80 ct: 0116aeb3a1c405c61b1ce47600b7ecd11d89b9c08c408b7e2d1e00a4d64696d12e68 81dc61688209a8207427f9 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: 9752b85fe8c73eda183f9e81 ct: 37ece0cf6741f443e9d73b9966dc0b228499bb21fbf313948327231e70a18380e080 529c0267f399ba7c539cc6 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: 9752b85fe8c73eda183f9e82 ct: d17b045cac963e45d55fd3692ec17f100df66ac06d91f3b6af8efa7ed3c8895550eb 753bc801fe4bd27005b4bd sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: 9752b85fe8c73eda183f9e84 ct: 50c523ae7c64cada96abea16ddf67a73d2914ec86a4cedb31a7e6257f7553ed24462 6ef79a57198192b2323384 sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: 9752b85fe8c73eda183f9e7f ct: 53d422295a6ce8fcc51e6f69e252e7195e64abf49252f347d8c25534f1865a6a17d9 49c65ce618ddc7d816111f sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: 9752b85fe8c73eda183f9f80 ct: 0dfcfc22ea768880b4160fec27ab10c75fb27766c6bb97aed373a9b6eae35d31afb0 8257401075cbb602ac5abb A.6.3.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 95] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 8d78748d632f95b8ce0c67d70f4ad1757e61e872b5941e146986804b3990154b exporter_context: 00 L: 32 exported_value: 80a4753230900ea785b6c80775092801fe91183746479f9b04c305e1db9d1f4d exporter_context: 54657374436f6e74657874 L: 32 exported_value: 620b176d737cf366bcc20d96adb54ec156978220879b67923689e6dca36210ed A.6.4. AuthPSK Setup Information mode: 3 kem_id: 18 kdf_id: 3 aead_id: 2 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 54272797b1fbc128a6967ff1fd606e0c67868f7762ce1421439cbc9e90ce1b28d5 66e6c2acbce712e48eebf236696eb680849d6873e9959395b2931975d61d38bd6c pkEm: 04000a5096a6e6e002c83517b494bfc2e36bfb8632fae8068362852b70d0ff71e5 60b15aff96741ecffb63d8ac3090c3769679009ac59a99a1feb4713c5f090fc0dbed01ad 73c45d29d369e36744e9ed37d12f80700c16d816485655169a5dd66e4ddf27f2acffe0f5 6f7f77ea2b473b4bf0518b975d9527009a3d14e5a4957e3e8a9074f8 skEm: 003430af19716084efeced1241bb1a5625b6c826f11ef31649095eb27952619e36 f62a79ea28001ac452fb20ddfbb66e62c6c0b1be03c0d28c97794a1fb638207a83 ikmR: 3db434a8bc25b27eb0c590dc64997ab1378a99f52b2cb5a5a5b2fa540888f6c0f0 9794c654f4468524e040e6b4eca2c9dcf229f908b9d318f960cc9e9baa92c5eee6 pkRm: 0401655b5d3b7cfafaba30851d25edc44c6dd17d99410efbed8591303b4dbeea8c b1045d5255f9a60384c3bbd4a3386ae6e6fab341dc1f8db0eed5f0ab1aaac6d7838e00da df8a1c2c64b48f89c633721e88369e54104b31368f26e35d04a442b0b428510fb23caada 686add16492f333b0f7ba74c391d779b788df2c38d7a7f4778009d91 skRm: 0053c0bc8c1db4e9e5c3e3158bfdd7fc716aef12db13c8515adf821dd692ba3ca5 3041029128ee19c8556e345c4bcb840bb7fd789f97fe10f17f0e2c6c2528072843 ikmS: 65d523d9b37e1273eb25ad0527d3a7bd33f67208dd1666d9904c6bc04969ae5831 a8b849e7ff642581f2c3e56be84609600d3c6bbdaded3f6989c37d2892b1e978d5 pkSm: 040013761e97007293d57de70962876b4926f69a52680b4714bee1d4236aa96c19 b840c57e80b14e91258f0a350e3f7ba59f3f091633aede4c7ec4fa8918323aa45d590107 6dec8eeb22899fda9ab9e1960003ff0535f53c02c40f2ae4cdc6070a3870b85b4bdd0bb7 7f1f889e7ee51f465a308f08c666ad3407f75dc046b2ff5a24dbe2ed skSm: 003f64675fc8914ec9e2b3ecf13585b26dbaf3d5d805042ba487a5070b8c5ac1d3 9b17e2161771cc1b4d0a3ba6e866f4ea4808684b56af2a49b5e5111146d45d9326 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 Barnes, et al. Expires 27 November 2021 [Page 96] Internet-Draft HPKE May 2021 enc: 04000a5096a6e6e002c83517b494bfc2e36bfb8632fae8068362852b70d0ff71e56 0b15aff96741ecffb63d8ac3090c3769679009ac59a99a1feb4713c5f090fc0dbed01ad7 3c45d29d369e36744e9ed37d12f80700c16d816485655169a5dd66e4ddf27f2acffe0f56 f7f77ea2b473b4bf0518b975d9527009a3d14e5a4957e3e8a9074f8 shared_secret: 9e1d5f62cb38229f57f68948a0fbc1264499910cce50ec62cb24188c5 b0a98868f3c1cfa8c5baa97b3f24db3cdd30df6e04eae83dc4347be8a981066c3b5b945 key_schedule_context: 0324497637cf18d6fbcc16e9f652f00244c981726f293bb781 9861e85e50c94f0be30e022ab081e18e6f299fd3d3d976a4bc590f85bc7711bfce32ee1a 7fb1c154ef45baa1f3a4b169e141feb957e48d03f28c837d8904c3d6775308c3d3faa75d d64adfa44e1a1141edf9349959b8f8e5291cbdc56f62b0ed6527d692e85b09a4 secret: 50a57775958037a04098e0054576cd3bc084d0d08d29548ba4befa5676b91eb4 dcd0752813a052c9a930d0aba6ca10b89dd690b64032dc635dece35d1bf4645c key: 1316ed34bd52374854ed0e5cb0394ca0a79b2d8ce7f15d5104f21acdfb594286 base_nonce: d9c64ec8deb8a0647fafe8ff exporter_secret: 6cb00ff99aebb2e4a05042ce0d048326dd2c03acd61a601b1038a65 398406a96ab8b5da3187412b2324089ea16ba4ff7e6f4fe55d281fc8ae5f2049032b69eb d A.6.4.1. Encryptions Barnes, et al. Expires 27 November 2021 [Page 97] Internet-Draft HPKE May 2021 sequence number: 0 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d30 nonce: d9c64ec8deb8a0647fafe8ff ct: 942a2a92e0817cf032ce61abccf4f3a7c5d21b794ed943227e07b7df2d6dd92c9b8a 9371949e65cca262448ab7 sequence number: 1 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d31 nonce: d9c64ec8deb8a0647fafe8fe ct: c0a83b5ec3d7933a090f681717290337b4fede5bfaa0a40ec29f93acad742888a151 3c649104c391c78d1d7f29 sequence number: 2 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d32 nonce: d9c64ec8deb8a0647fafe8fd ct: 2847b2e0ce0b9da8fca7b0e81ff389d1682ee1b388ed09579b145058b5af6a93a85d d50d9f417dc88f2c785312 sequence number: 4 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d34 nonce: d9c64ec8deb8a0647fafe8fb ct: fbd9948ab9ac4a9cb9e295c07273600e6a111a3a89241d3e2178f39d532a2ec5c15b 9b0c6937ac84c88e0ca76f sequence number: 255 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323535 nonce: d9c64ec8deb8a0647fafe800 ct: 63113a870131b567db8f39a11b4541eafbd2d3cf3a9bf9e5c1cfcb41e52f9027310b 82a4868215959131694d15 sequence number: 256 pt: 4265617574792069732074727574682c20747275746820626561757479 aad: 436f756e742d323536 nonce: d9c64ec8deb8a0647fafe9ff ct: 24f9d8dadd2107376ccd143f70f9bafcd2b21d8117d45ff327e9a78f603a32606e42 a6a8bdb57a852591d20907 A.6.4.2. Exported Values Barnes, et al. Expires 27 November 2021 [Page 98] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: a39502ef5ca116aa1317bd9583dd52f15b0502b71d900fc8a622d19623d0cb5d exporter_context: 00 L: 32 exported_value: 749eda112c4cfdd6671d84595f12cd13198fc3ef93ed72369178f344fe6e09c3 exporter_context: 54657374436f6e74657874 L: 32 exported_value: f8b4e72cefbff4ca6c4eabb8c0383287082cfcbb953d900aed4959afd0017095 A.7. DHKEM(X25519, HKDF-SHA256), HKDF-SHA256, Export-Only AEAD A.7.1. Base Setup Information mode: 0 kem_id: 32 kdf_id: 1 aead_id: 65535 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 55bc245ee4efda25d38f2d54d5bb6665291b99f8108a8c4b686c2b14893ea5d9 pkEm: e5e8f9bfff6c2f29791fc351d2c25ce1299aa5eaca78a757c0b4fb4bcd830918 skEm: 095182b502f1f91f63ba584c7c3ec473d617b8b4c2cec3fad5af7fa6748165ed ikmR: 683ae0da1d22181e74ed2e503ebf82840deb1d5e872cade20f4b458d99783e31 pkRm: 194141ca6c3c3beb4792cd97ba0ea1faff09d98435012345766ee33aae2d7664 skRm: 33d196c830a12f9ac65d6e565a590d80f04ee9b19c83c87f2c170d972a812848 enc: e5e8f9bfff6c2f29791fc351d2c25ce1299aa5eaca78a757c0b4fb4bcd830918 shared_secret: e81716ce8f73141d4f25ee9098efc968c91e5b8ce52ffff59d64039e82918b66 key_schedule_context: 009bd09219212a8cf27c6bb5d54998c5240793a70ca0a89223 4bd5e082bc619b6a3f4c22aa6d9a0424c2b4292fdf43b8257df93c2f6adbf6ddc9c64fee 26bdd292 secret: 04d64e0620aa047e9ab833b0ebcd4ff026cefbe44338fd7d1a93548102ee01af key: base_nonce: exporter_secret: 79dc8e0509cf4a3364ca027e5a0138235281611ca910e435e8ed58167c72f79b A.7.1.1. Exported Values Barnes, et al. Expires 27 November 2021 [Page 99] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 7a36221bd56d50fb51ee65edfd98d06a23c4dc87085aa5866cb7087244bd2a36 exporter_context: 00 L: 32 exported_value: d5535b87099c6c3ce80dc112a2671c6ec8e811a2f284f948cec6dd1708ee33f0 exporter_context: 54657374436f6e74657874 L: 32 exported_value: ffaabc85a776136ca0c378e5d084c9140ab552b78f039d2e8775f26efff4c70e A.7.2. PSK Setup Information mode: 1 kem_id: 32 kdf_id: 1 aead_id: 65535 info: 4f6465206f6e2061204772656369616e2055726e ikmE: c51211a8799f6b8a0021fcba673d9c4067a98ebc6794232e5b06cb9febcbbdf5 pkEm: d3805a97cbcd5f08babd21221d3e6b362a700572d14f9bbeb94ec078d051ae3d skEm: 1d72396121a6a826549776ef1a9d2f3a2907fc6a38902fa4e401afdb0392e627 ikmR: 5e0516b1b29c0e13386529da16525210c796f7d647c37eac118023a6aa9eb89a pkRm: d53af36ea5f58f8868bb4a1333ed4cc47e7a63b0040eb54c77b9c8ec456da824 skRm: 98f304d4ecb312689690b113973c61ffe0aa7c13f2fbe365e48f3ed09e5a6a0c psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: d3805a97cbcd5f08babd21221d3e6b362a700572d14f9bbeb94ec078d051ae3d shared_secret: 024573db58c887decb4c57b6ed39f2c9a09c85600a8a0ecb11cac24c6aaec195 key_schedule_context: 01446fb1fe2632a0a338f0a85ed1f3a0ac475bdea2cd72f8c7 13b3a46ee737379a3f4c22aa6d9a0424c2b4292fdf43b8257df93c2f6adbf6ddc9c64fee 26bdd292 secret: 638b94532e0d0bf812cf294f36b97a5bdcb0299df36e22b7bb6858e3c113080b key: base_nonce: exporter_secret: 04261818aeae99d6aba5101bd35ddf3271d909a756adcef0d41389d9ed9ab153 A.7.2.1. Exported Values Barnes, et al. Expires 27 November 2021 [Page 100] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: be6c76955334376aa23e936be013ba8bbae90ae74ed995c1c6157e6f08dd5316 exporter_context: 00 L: 32 exported_value: 1721ed2aa852f84d44ad020c2e2be4e2e6375098bf48775a533505fd56a3f416 exporter_context: 54657374436f6e74657874 L: 32 exported_value: 7c9d79876a288507b81a5a52365a7d39cc0fa3f07e34172984f96fec07c44cba A.7.3. Auth Setup Information mode: 2 kem_id: 32 kdf_id: 1 aead_id: 65535 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 43b078912a54b591a7b09b16ce89a1955a9dd60b29fb611e044260046e8b061b pkEm: 5ac1671a55c5c3875a8afe74664aa8bc68830be9ded0c5f633cd96400e8b5c05 skEm: 83d3f217071bbf600ba6f081f6e4005d27b97c8001f55cb5ff6ea3bbea1d9295 ikmR: fc9407ae72ed614901ebf44257fb540f617284b5361cfecd620bafc4aba36f73 pkRm: ffd7ac24694cb17939d95feb7c4c6539bb31621deb9b96d715a64abdd9d14b10 skRm: ed88cda0e91ca5da64b6ad7fc34a10f096fa92f0b9ceff9d2c55124304ed8b4a ikmS: 2ff4c37a17b2e54046a076bf5fea9c3d59250d54d0dc8572bc5f7c046307040c pkSm: 89eb1feae431159a5250c5186f72a15962c8d0debd20a8389d8b6e4996e14306 skSm: c85f136e06d72d28314f0e34b10aadc8d297e9d71d45a5662c2b7c3b9f9f9405 enc: 5ac1671a55c5c3875a8afe74664aa8bc68830be9ded0c5f633cd96400e8b5c05 shared_secret: e204156fd17fd65b132d53a0558cd67b7c0d7095ee494b00f47d686eb78f8fb3 key_schedule_context: 029bd09219212a8cf27c6bb5d54998c5240793a70ca0a89223 4bd5e082bc619b6a3f4c22aa6d9a0424c2b4292fdf43b8257df93c2f6adbf6ddc9c64fee 26bdd292 secret: 355e7ef17f438db43152b7fb45a0e2f49a8bf8956d5dddfec1758c0f0eb1b5d5 key: base_nonce: exporter_secret: 276d87e5cb0655c7d3dad95e76e6fc02746739eb9d968955ccf8a6346c97509e A.7.3.1. Exported Values Barnes, et al. Expires 27 November 2021 [Page 101] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: 83c1bac00a45ed4cb6bd8a6007d2ce4ec501f55e485c5642bd01bf6b6d7d6f0a exporter_context: 00 L: 32 exported_value: 08a1d1ad2af3ef5bc40232a64f920650eb9b1034fac3892f729f7949621bf06e exporter_context: 54657374436f6e74657874 L: 32 exported_value: ff3b0e37a9954247fea53f251b799e2edd35aac7152c5795751a3da424feca73 A.7.4. AuthPSK Setup Information mode: 3 kem_id: 32 kdf_id: 1 aead_id: 65535 info: 4f6465206f6e2061204772656369616e2055726e ikmE: 94efae91e96811a3a49fd1b20eb0344d68ead6ac01922c2360779aa172487f40 pkEm: 81cbf4bd7eee97dd0b600252a1c964ea186846252abb340be47087cc78f3d87c skEm: a2b43f5c67d0d560ee04de0122c765ea5165e328410844db97f74595761bbb81 ikmR: 4dfde6fadfe5cb50fced4034e84e6d3a104aa4bf2971360032c1c0580e286663 pkRm: f47cd9d6993d2e2234eb122b425accfb486ee80f89607b087094e9f413253c2d skRm: c4962a7f97d773a47bdf40db4b01dc6a56797c9e0deaab45f4ea3aa9b1d72904 ikmS: 26c12fef8d71d13bbbf08ce8157a283d5e67ecf0f345366b0e90341911110f1b pkSm: 29a5bf3867a6128bbdf8e070abe7fe70ca5e07b629eba5819af73810ee20112f skSm: 6175b2830c5743dff5b7568a7e20edb1fe477fb0487ca21d6433365be90234d0 psk: 0247fd33b913760fa1fa51e1892d9f307fbe65eb171e8132c2af18555a738b82 psk_id: 456e6e796e20447572696e206172616e204d6f726961 enc: 81cbf4bd7eee97dd0b600252a1c964ea186846252abb340be47087cc78f3d87c shared_secret: d69246bcd767e579b1eec80956d7e7dfbd2902dad920556f0de69bd54054a2d1 key_schedule_context: 03446fb1fe2632a0a338f0a85ed1f3a0ac475bdea2cd72f8c7 13b3a46ee737379a3f4c22aa6d9a0424c2b4292fdf43b8257df93c2f6adbf6ddc9c64fee 26bdd292 secret: c15c5bec374f2087c241d3533c6ec48e1c60a21dd00085619b2ffdd84a7918c3 key: base_nonce: exporter_secret: 695b1faa479c0e0518b6414c3b46e8ef5caea04c0a192246843765ae6a8a78e0 A.7.4.1. Exported Values Barnes, et al. Expires 27 November 2021 [Page 102] Internet-Draft HPKE May 2021 exporter_context: L: 32 exported_value: dafd8beb94c5802535c22ff4c1af8946c98df2c417e187c6ccafe45335810b58 exporter_context: 00 L: 32 exported_value: 7346bb0b56caf457bcc1aa63c1b97d9834644bdacac8f72dbbe3463e4e46b0dd exporter_context: 54657374436f6e74657874 L: 32 exported_value: 84f3466bd5a03bde6444324e63d7560e7ac790da4e5bbab01e7c4d575728c34a Authors' Addresses Richard L. Barnes Cisco Email: rlb@ipv.sx Karthik Bhargavan Inria Email: karthikeyan.bhargavan@inria.fr Benjamin Lipp Inria Email: ietf@benjaminlipp.de Christopher A. Wood Cloudflare Email: caw@heapingbits.net Barnes, et al. Expires 27 November 2021 [Page 103]