JSON Web Algorithms (JWA)
Microsoft
mbj@microsoft.com
http://self-issued.info/
Security
JOSE Working Group
RFC
Request for Comments
I-D
Internet-Draft
JavaScript Object Notation
JSON
JSON Web Token
JWT
JSON Web Signature
JWS
JSON Web Encryption
JWE
JSON Web Algorithms
JWA
The JSON Web Algorithms (JWA) specification enumerates
cryptographic algorithms and identifiers to be used with the
JSON Web Signature (JWS) and
JSON Web Encryption (JWE) specifications.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described
in RFC 2119.
The JSON Web Algorithms (JWA) specification enumerates
cryptographic algorithms and identifiers to be used with the
JSON Web Signature (JWS) and
JSON Web Encryption (JWE) specifications.
Enumerating the algorithms and identifiers for them in this
specification, rather than in the JWS and JWE
specifications, is intended to allow them to remain unchanged
in the face of changes in the set of required, recommended,
optional, and deprecated algorithms over time.
This specification also describes the semantics and operations
that are specific to these algorithms and algorithm families.
This specification uses the terminology defined by the
JSON Web Signature (JWS) and
JSON Web Encryption (JWE) specifications.
JWS uses cryptographic algorithms to digitally sign or MAC the contents
of the JWS Header and the JWS Payload. The
use of the following algorithms for producing JWSs is defined in
this section.
The table below is the set of
alg (algorithm) header
parameter values defined by this specification for use with JWS, each of which
is explained in more detail in the following sections:
alg Parameter Value
Digital Signature or MAC Algorithm
HS256
HMAC using SHA-256 hash algorithm
HS384
HMAC using SHA-384 hash algorithm
HS512
HMAC using SHA-512 hash algorithm
RS256
RSA using SHA-256 hash algorithm
RS384
RSA using SHA-384 hash algorithm
RS512
RSA using SHA-512 hash algorithm
ES256
ECDSA using P-256 curve and SHA-256 hash algorithm
ES384
ECDSA using P-384 curve and SHA-384 hash algorithm
ES512
ECDSA using P-521 curve and SHA-512 hash algorithm
none
No digital signature or MAC value included
See for a table cross-referencing the
digital signature and MAC alg (algorithm)
values used in this specification
with the equivalent identifiers used by other
standards and software packages.
Of these algorithms, only HMAC SHA-256 and none MUST be implemented by
conforming JWS implementations. It is RECOMMENDED that
implementations also support the RSA SHA-256 and ECDSA P-256
SHA-256 algorithms. Support for other algorithms and key
sizes is OPTIONAL.
Hash-based Message Authentication Codes (HMACs) enable one to
use a secret plus a cryptographic hash function to generate a
Message Authentication Code (MAC). This can be used to
demonstrate that the MAC matches the hashed content, in this
case the JWS Secured Input, which therefore demonstrates that
whoever generated the MAC was in possession of the secret.
The means of exchanging the shared key is outside the scope
of this specification.
The algorithm for implementing and validating HMACs is
provided in RFC 2104. This
section defines the use of the HMAC SHA-256, HMAC SHA-384,
and HMAC SHA-512 cryptographic hash functions as defined in
FIPS 180-3. The
alg (algorithm) header parameter values
HS256, HS384, and HS512 are used in the JWS Header
to indicate that the Encoded JWS Signature contains a base64url
encoded HMAC value using the respective hash function.
A key of the same size as the hash output (for instance, 256
bits for HS256) or larger MUST
be used with this algorithm.
The HMAC SHA-256 MAC is generated as follows:
Apply the HMAC SHA-256 algorithm to the bytes of the UTF-8 representation
of the JWS Secured Input
(which is the same as the ASCII representation)
using the shared key to produce an HMAC value.
Base64url encode the resulting HMAC value.

The output is the Encoded JWS Signature for that JWS.
The HMAC SHA-256 MAC for a JWS is validated as follows:
Apply the HMAC SHA-256 algorithm to the bytes of the UTF-8 representation
of the JWS Secured Input
(which is the same as the ASCII representation)
of the JWS using the shared key.
Base64url encode the resulting HMAC value.
If the Encoded JWS Signature and the base64url encoded HMAC
value exactly match, then one has confirmation that the
shared key was used to generate the HMAC on the JWS and that the
contents of the JWS have not be tampered with.
If the validation fails, the JWS MUST be rejected.

Alternatively, the Encoded JWS Signature MAY be base64url
decoded to produce the JWS Signature and this value can
be compared with the computed HMAC value, as this
comparison produces the same result as comparing the
encoded values.
Securing content with the HMAC SHA-384 and HMAC SHA-512 algorithms is
performed identically to the procedure for HMAC SHA-256 - just
with correspondingly larger minimum key sizes and result values.
This section defines the use of the RSASSA-PKCS1-v1_5
digital signature algorithm as defined in RFC
3447, Section 8.2 (commonly known as PKCS#1), using
SHA-256, SHA-384, or SHA-512 as the hash function. The
RSASSA-PKCS1-v1_5 algorithm is described in FIPS 186-3, Section 5.5, and the
SHA-256, SHA-384, and SHA-512 cryptographic hash functions
are defined in FIPS 180-3.
The alg (algorithm) header
parameter values RS256, RS384, and RS512 are used in the JWS Header
to indicate that the Encoded JWS Signature contains a base64url
encoded RSA digital signature using the respective hash function.
A key of size 2048 bits or larger MUST be used with these algorithms.
Note that while Section 8 of RFC
3447 explicitly calls for people not to adopt
RSASSA-PKCS1 for new applications and instead requests that
people transition to RSASSA-PSS, for interoperability
reasons, this specification does use RSASSA-PKCS1 because it
commonly implemented.
The RSA SHA-256 digital signature is generated as follows:
Generate a digital signature of the bytes of the UTF-8 representation
of the JWS Secured Input
(which is the same as the ASCII representation)
using RSASSA-PKCS1-V1_5-SIGN
and the SHA-256 hash function with the desired private
key. The output will be a byte array.
Base64url encode the resulting byte array.

The output is the Encoded JWS Signature for that JWS.
The RSA SHA-256 digital signature for a JWS is validated as follows:
Take the Encoded JWS Signature and base64url decode it into
a byte array. If decoding fails, the JWS MUST
be rejected.
Submit the bytes of the UTF-8 representation of the JWS Secured Input
(which is the same as the ASCII representation)
and the public key corresponding to the private key used
by the signer to the RSASSA-PKCS1-V1_5-VERIFY algorithm
using SHA-256 as the hash function.
If the validation fails, the JWS MUST be rejected.

Signing with the RSA SHA-384 and RSA SHA-512 algorithms is
performed identically to the procedure for RSA SHA-256 - just
with correspondingly larger result values.
The Elliptic Curve Digital Signature Algorithm (ECDSA) is
defined by FIPS 186-3. ECDSA
provides for the use of Elliptic Curve cryptography, which is
able to provide equivalent security to RSA cryptography but
using shorter key sizes and with greater processing
speed. This means that ECDSA digital signatures will be substantially
smaller in terms of length than equivalently strong RSA
digital signatures.
This specification defines the use of ECDSA with the P-256
curve and the SHA-256 cryptographic hash function, ECDSA
with the P-384 curve and the SHA-384 hash function, and
ECDSA with the P-521 curve and the SHA-512 hash
function. The P-256, P-384, and P-521 curves are also
defined in FIPS 186-3. The alg (algorithm) header parameter values ES256, ES384, and ES512 are used in the JWS Header
to indicate that the Encoded JWS Signature contains a base64url
encoded ECDSA P-256 SHA-256, ECDSA P-384 SHA-384, or ECDSA
P-521 SHA-512 digital signature, respectively.
A key of size 160 bits or larger MUST be used with these algorithms.
The ECDSA P-256 SHA-256 digital signature is generated as follows:
Generate a digital signature of the bytes of the UTF-8 representation
of the JWS Secured Input
(which is the same as the ASCII representation)
using ECDSA P-256 SHA-256 with
the desired private key. The output will be the EC point
(R, S), where R and S are unsigned integers.
Turn R and S into byte arrays in big endian order. Each
array will be 32 bytes long.
Concatenate the two byte arrays in the order R and then S.
Base64url encode the resulting 64 byte array.

The output is the Encoded JWS Signature for the JWS.
The ECDSA P-256 SHA-256 digital signature for a JWS is validated as follows:
Take the Encoded JWS Signature and base64url decode it into
a byte array. If decoding fails, the JWS MUST
be rejected.
The output of the base64url decoding MUST be a 64 byte
array.
Split the 64 byte array into two 32 byte arrays. The first
array will be R and the second S
(with both being in big endian byte order).
Submit the bytes of the UTF-8 representation of the JWS Secured Input
(which is the same as the ASCII representation),
R, S and the public key (x, y) to the ECDSA P-256
SHA-256 validator.
If the validation fails, the JWS MUST be rejected.

The ECDSA validator will then determine if the digital
signature is valid, given the inputs. Note that ECDSA digital
signature contains a value referred to as K, which is a random
number generated for each digital signature instance. This
means that two ECDSA digital signatures using exactly the same
input parameters will output different signature values because
their K values will be different. The consequence of this is
that one must validate an ECDSA digital signature by submitting the
previously specified inputs to an ECDSA validator.
Signing with the ECDSA P-384 SHA-384 and ECDSA P-521 SHA-512
algorithms is performed identically to the procedure for ECDSA
P-256 SHA-256 - just with correspondingly larger result values.
To support use cases where the content is secured by a means
other than a digital signature or MAC value, JWSs MAY also
be created without them. These are called "Plaintext JWSs".
Plaintext JWSs MUST use the alg
value none, and are formatted
identically to other JWSs, but with an empty JWS Signature
value.
Additional algorithms MAY be used to protect JWSs with
corresponding alg (algorithm)
header parameter values being defined to refer to them.
New alg header parameter values SHOULD
either be defined in the IANA JSON Web Signature and Encryption Algorithms
registry or be
a URI that contains a collision resistant namespace.
In particular, it is permissible to use the algorithm identifiers defined in
XML DSIG,
XML DSIG 2.0,
and related specifications as
alg values.
As indicated by the common registry, JWSs and JWEs share a
common alg value space.
The values used by the two specifications MUST be distinct,
as the alg value MAY be used
to determine whether the object is a JWS or JWE.
Likewise, additional reserved header parameter names MAY be defined
via the IANA
JSON Web Signature and Encryption Header Parameters registry
.
As indicated by the common registry, JWSs and JWEs share a
common header parameter space; when a parameter is used by
both specifications, its usage must be compatible
between the specifications.
JWE uses cryptographic algorithms to encrypt the Content
Master Key (CMK) and the Plaintext. This section
specifies a set of specific algorithms for these purposes.
The table below is the set of alg (algorithm) header parameter values
that are defined by this specification for use with JWE.
These algorithms are used to encrypt the CMK, producing the
JWE Encrypted Key, or to use key agreement to agree upon the CMK.
alg Parameter Value
Key Encryption or Agreement Algorithm
RSA1_5
RSA using RSA-PKCS1-1.5 padding, as defined in RFC 3447
RSA-OAEP
RSA using Optimal Asymmetric Encryption Padding (OAEP), as
defined in RFC 3447
ECDH-ES
Elliptic Curve Diffie-Hellman Ephemeral Static, as defined
in RFC 6090, and using the
Concat KDF, as defined in Section 5.8.1 of ,
where the Digest Method is SHA-256 and all OtherInfo
parameters are the empty bit string
A128KW
Advanced Encryption Standard (AES) Key Wrap Algorithm using
128 bit keys, as defined in RFC
3394
A256KW
Advanced Encryption Standard (AES) Key Wrap Algorithm using
256 bit keys, as defined in RFC
3394
The table below is the set of
enc (encryption method) header parameter values that
are defined by this specification for use with JWE. These algorithms are used
to encrypt the Plaintext, which produces the Ciphertext.
enc Parameter Value
Block Encryption Algorithm
A128CBC
Advanced Encryption Standard (AES) using 128 bit keys in
Cipher Block Chaining (CBC) mode using PKCS #5 padding,
as defined in
and
A256CBC
Advanced Encryption Standard (AES) using 256 bit keys in
Cipher Block Chaining (CBC) mode using PKCS #5 padding,
as defined in
and
A128GCM
Advanced Encryption Standard (AES) using 128 bit keys in
Galois/Counter Mode (GCM), as defined in
and
A256GCM
Advanced Encryption Standard (AES) using 256 bit keys in
Galois/Counter Mode (GCM), as defined in
and
See for a table cross-referencing the
encryption alg (algorithm) and
enc (encryption method)
values used in this specification
with the equivalent identifiers used by other
standards and software packages.
Of these alg and enc algorithms,
only RSA-PKCS1-1.5 with 2048 bit keys,
AES-128-KW, AES-256-KW,
AES-128-CBC, and AES-256-CBC MUST be implemented by conforming JWE
implementations. It is RECOMMENDED that implementations also
support ECDH-ES with 256 bit keys, AES-128-GCM, and
AES-256-GCM. Support for other algorithms and key sizes is
OPTIONAL.
The table below is the set of
int (integrity algorithm) header
parameter values defined by this specification for use with JWE.
Note that these are the HMAC SHA subset of the
alg (algorithm) header parameter values
defined for use with JWS .
/>
int Parameter Value
Algorithm
HS256
HMAC using SHA-256 hash algorithm
HS384
HMAC using SHA-384 hash algorithm
HS512
HMAC using SHA-512 hash algorithm
Of these int algorithms,
only HMAC SHA-256 MUST be implemented by
conforming JWE implementations. It is RECOMMENDED that
implementations also support the RSA SHA-256 and ECDSA P-256
SHA-256 algorithms.
This section defines the specifics of encrypting a JWE CMK with
RSA using RSA-PKCS1-1.5 padding, as defined in RFC 3447.
The alg header parameter value
RSA1_5 is used in this case.
A key of size 2048 bits or larger MUST be used with this algorithm.
This section defines the specifics of encrypting a JWE CMK with
RSA using Optimal Asymmetric Encryption Padding (OAEP), as
defined in RFC 3447.
The alg header parameter value
RSA-OAEP is used in this case.
A key of size 2048 bits or larger MUST be used with this algorithm.
This section defines the specifics of agreeing upon a JWE CMK with
Elliptic Curve Diffie-Hellman Ephemeral Static, as defined
in RFC 6090, and using the
Concat KDF, as defined in Section 5.8.1 of ,
where the Digest Method is SHA-256 and all OtherInfo
parameters are the empty bit string.
The alg header parameter value
ECDH-ES is used in this case.
A key of size 160 bits or larger MUST be used for the
Elliptic Curve keys used with this algorithm.
The output of the Concat KDF MUST be a key of the
same length as that used by the
enc algorithm.
An epk (ephemeral public key)
value MUST only be used for a single key agreement
transaction.
This section defines the specifics of encrypting a JWE CMK with
the Advanced Encryption Standard (AES) Key Wrap Algorithm using
128 or 256 bit keys, as defined in RFC
3394.
The alg header parameter values
A128KW or A256KW
are used in this case.
This section defines the specifics of encrypting the JWE Plaintext with
Advanced Encryption Standard (AES) in Cipher Block Chaining (CBC) mode
using PKCS #5 padding using 128 or 256 bit keys,
as defined in
and .
The enc header parameter values
A128CBC or A256CBC
are used in this case.
Use of an Initialization Vector (IV) of size 128 bits is
RECOMMENDED with this algorithm.
This section defines the specifics of encrypting the JWE Plaintext with
Advanced Encryption Standard (AES) in Galois/Counter Mode (GCM)
using 128 or 256 bit keys,
as defined in
and .
The enc header parameter values
A128GCM or A256GCM
are used in this case.
Use of an Initialization Vector (IV) of size 96 bits is
REQUIRED with this algorithm.
The "additional authenticated data" parameter value for the
encryption is the concatenation of the Encoded JWE Header, a
period ('.') character, and the Encoded JWE Encrypted Key.
The requested size of the "authentication tag" output MUST be
the same as the key size (for instance, 128 bits for
A128GCM).
As GCM is an AEAD algorithm, the JWE Integrity Value is set
to be the "authentication tag" value produced by the encryption.
This section defines the specifics of computing a JWE Integrity Value with
HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512
as defined in FIPS 180-3.
The int header parameter values
HS256, HS384,
or HS512
are used in this case.
A key of the same size as the hash output (for instance, 256
bits for HS256) or larger MUST
be used with this algorithm.
Additional algorithms MAY be used to protect JWEs with
corresponding alg (algorithm),
enc (encryption method), and
int (integrity algorithm)
header parameter values being
defined to refer to them. New
alg,
enc, and
int
header parameter values SHOULD
either be defined in the IANA JSON Web Signature and Encryption Algorithms
registry or be
a URI that contains a collision resistant namespace.
In particular, it is permissible to use the algorithm identifiers defined in
XML Encryption,
XML Encryption 1.1,
and related specifications as
alg,
enc, and
int values.
As indicated by the common registry, JWSs and JWEs share a
common alg value space.
The values used by the two specifications MUST be distinct,
as the alg value MAY be used
to determine whether the object is a JWS or JWE.
Likewise, additional reserved header parameter names MAY be defined
via the IANA
JSON Web Signature and Encryption Header Parameters registry
.
As indicated by the common registry, JWSs and JWEs share a
common header parameter space; when a parameter is used by
both specifications, its usage must be compatible
between the specifications.
A JSON Web Key (JWK) is a JSON data
structure that represents a public key. A JSON Web Key Set
(JWK Set) is a JSON data structure for representing a set of JWKs.
This section specifies a set of algorithm families to be used
for those public keys and the algorithm family specific
parameters for representing those keys.
The table below is the set of
alg (algorithm family) parameter
values that are defined by this specification for use in JWKs.
alg Parameter Value
Algorithm Family
EC
Elliptic Curve key family
RSA
RSA key family
JWKs can represent Elliptic Curve keys. In
this case, the alg
member value MUST be EC.
Furthermore, these additional members MUST be present:
The crv (curve) member identifies
the cryptographic curve used with the key. Values
defined by this specification are P-256, P-384 and P-521. Additional crv values MAY be used, provided
they are understood by implementations using that Elliptic Curve
key.
The crv value is case sensitive.
Its value MUST be a string.
The x (x coordinate) member contains the
x coordinate for the elliptic curve point. It is
represented as the base64url encoding of the
coordinate's big endian representation.
The y (y coordinate) member contains the
y coordinate for the elliptic curve point. It is
represented as the base64url encoding of the
coordinate's big endian representation.
JWKs can represent RSA keys. In
this case, the alg
member value MUST be RSA.
Furthermore, these additional members MUST be present:
The mod (modulus) member contains
the modulus value for the RSA public key. It is
represented as the base64url encoding of the value's big
endian representation.
The exp (exponent) member contains
the exponent value for the RSA public key. It is
represented as the base64url encoding of the value's big
endian representation.
Public keys using additional algorithm families MAY be
represented using JWK data structures with corresponding
alg (algorithm family) parameter
values being defined to refer to them.
New alg parameter values SHOULD
either be defined in the IANA JSON Web Key Algorithm Families
registry or be
a URI that contains a collision resistant namespace.
Likewise, parameters for representing keys for additional
algorithm families or additional key properties
SHOULD either be defined in the IANA JSON Web Key Parameters registry
or be
a URI that contains a collision resistant namespace.
This specification establishes the
IANA JSON Web Signature and Encryption Header Parameters registry
for reserved JWS and JWE header parameter names.
Inclusion in the registry is RFC Required in the
RFC 5226 sense.
The registry records the reserved header parameter name
and a reference to the RFC that defines it.
This specification registers the header parameter names defined in
JSON Web Signature (JWS) , Section 4.1 and
JSON Web Encryption (JWE) , Section 4.1.
This specification establishes the
IANA JSON Web Signature and Encryption Algorithms registry
for values of the JWS and JWE
alg (algorithm),
enc (encryption method), and
int (integrity algorithm)
header parameters.
Inclusion in the registry is RFC Required in the
RFC 5226 sense.
The registry records the algorithm usage
alg,
enc, or
int, the value,
and a pointer to the RFC that defines it.
This specification registers the values defined in
,
,
, and
.
This specification establishes the
IANA JSON Web Signature and Encryption "typ" Values registry
for values of the JWS and JWE
typ (type)
header parameter.
Inclusion in the registry is RFC Required in the
RFC 5226 sense.
It is RECOMMENDED that all registered typ values also register a
MIME Media Type RFC 2045
that the registered value is a short name for.
The registry records the
typ value,
the MIME type value that it is an abbreviation for (if any),
and a pointer to the RFC that defines it.
MIME Media Type RFC 2045
values MUST NOT be directly registered as new
typ values; rather, new
typ values MAY be registered
as short names for MIME types.
This specification establishes the
IANA JSON Web Key Parameters registry
for reserved JWK parameter names.
Inclusion in the registry is RFC Required in the
RFC 5226 sense.
The registry records the reserved parameter name
and a reference to the RFC that defines it.
This specification registers the parameter names defined in
JSON Web Key (JWK) , Section 4.2,
JSON Web Encryption (JWE) , Section 4.1,
, and .
This specification establishes the
IANA JSON Web Key Algorithm Families registry
for values of the JWK
alg (algorithm family) parameter.
Inclusion in the registry is RFC Required in the
RFC 5226 sense.
The registry records the alg value
and a pointer to the RFC that defines it.
This specification registers the values defined in
.
The security considerations in the JWS, JWE, and JWK
specifications also apply to this specification.
Eventually the algorithms and/or key sizes currently described
in this specification will no longer be considered
sufficiently secure and will be removed. Therefore,
implementers and deployments must be prepared for this
eventuality.
The following items remain to be done in this draft:
Find values for encryption algorithm cross-reference table
currently listed as "TBD" or determine that they do not exist.

Secure Hash Standard (SHS)
National Institute of Standards and
Technology
Digital Signature Standard (DSS)
National Institute of Standards and
Technology
Advanced Encryption Standard (AES)
National Institute of Standards and Technology (NIST)
Recommendation for Block Cipher Modes of Operation
National Institute of Standards and Technology (NIST)
Recommendation for Block Cipher Modes of Operation:
Galois/Counter Mode (GCM) and GMAC
National Institute of Standards and Technology (NIST)
Recommendation for Pair-Wise Key Establishment Schemes Using Discrete Logarithm Cryptography (Revised)
National Institute of Standards and Technology (NIST)
JSON Web Signature (JWS)
Microsoft
mbj@microsoft.com
http://self-issued.info/
Ping Identity
ve7jtb@ve7jtb.com
Nomura Research Institute
n-sakimura@nri.co.jp
JSON Web Encryption (JWE)
Microsoft
mbj@microsoft.com
http://self-issued.info/
RTFM, Inc.
ekr@rtfm.com
Cisco Systems, Inc.
jhildebr@cisco.com
JSON Web Key (JWK)
Microsoft
mbj@microsoft.com
http://self-issued.info/
Magic Signatures
JSON Simple Sign
independent
Nomura Research Institute
JSON Simple Encryption
independent
Nomura Research Institute
Canvas Applications
Java Cryptography Architecture
This appendix contains a table cross-referencing the
digital signature and MAC alg (algorithm)
values used in this specification
with the equivalent identifiers used by other standards and
software packages. See XML DSIG,
XML DSIG 2.0,
and Java Cryptography Architecture
for more information about the names defined by those
documents.
Algorithm
JWS
XML DSIG
JCA
OID
HMAC using SHA-256 hash algorithm
HS256
http://www.w3.org/2001/04/xmldsig-more#hmac-sha256
HmacSHA256
1.2.840.113549.2.9
HMAC using SHA-384 hash algorithm
HS384
http://www.w3.org/2001/04/xmldsig-more#hmac-sha384
HmacSHA384
1.2.840.113549.2.10
HMAC using SHA-512 hash algorithm
HS512
http://www.w3.org/2001/04/xmldsig-more#hmac-sha512
HmacSHA512
1.2.840.113549.2.11
RSA using SHA-256 hash algorithm
RS256
http://www.w3.org/2001/04/xmldsig-more#rsa-sha256
SHA256withRSA
1.2.840.113549.1.1.11
RSA using SHA-384 hash algorithm
RS384
http://www.w3.org/2001/04/xmldsig-more#rsa-sha384
SHA384withRSA
1.2.840.113549.1.1.12
RSA using SHA-512 hash algorithm
RS512
http://www.w3.org/2001/04/xmldsig-more#rsa-sha512
SHA512withRSA
1.2.840.113549.1.1.13
ECDSA using P-256 curve and SHA-256 hash algorithm
ES256
http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha256
SHA256withECDSA
1.2.840.10045.4.3.2
ECDSA using P-384 curve and SHA-384 hash algorithm
ES384
http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha384
SHA384withECDSA
1.2.840.10045.4.3.3
ECDSA using P-521 curve and SHA-512 hash algorithm
ES512
http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha512
SHA512withECDSA
1.2.840.10045.4.3.4
This appendix contains a table cross-referencing the alg (algorithm) and enc (encryption method)
values used in this specification with the equivalent
identifiers used by other standards and software packages.
See
XML Encryption,
XML Encryption 1.1,
and Java Cryptography Architecture for more
information about the names defined by those documents.
Algorithm
JWE
XML ENC
JCA
RSA using RSA-PKCS1-1.5 padding
RSA1_5
http://www.w3.org/2001/04/xmlenc#rsa-1_5
RSA/ECB/PKCS1Padding
RSA using Optimal Asymmetric Encryption Padding (OAEP)
RSA-OAEP
http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p
RSA/ECB/OAEPWithSHA-1AndMGF1Padding
Elliptic Curve Diffie-Hellman Ephemeral Static
ECDH-ES
http://www.w3.org/2009/xmlenc11#ECDH-ES
TBD
Advanced Encryption Standard (AES) Key Wrap Algorithm RFC 3394 using 128 bit keys
A128KW
http://www.w3.org/2001/04/xmlenc#kw-aes128
TBD
Advanced Encryption Standard (AES) Key Wrap Algorithm RFC 3394 using 256 bit keys
A256KW
http://www.w3.org/2001/04/xmlenc#kw-aes256
TBD
Advanced Encryption Standard (AES) using 128 bit keys in
Cipher Block Chaining (CBC) mode using PKCS #5 padding
A128CBC
http://www.w3.org/2001/04/xmlenc#aes128-cbc
AES/CBC/PKCS5Padding
Advanced Encryption Standard (AES) using 256 bit keys in
Cipher Block Chaining (CBC) mode using PKCS #5 padding
A256CBC
http://www.w3.org/2001/04/xmlenc#aes256-cbc
AES/CBC/PKCS5Padding
Advanced Encryption Standard (AES) using 128 bit keys in
Galois/Counter Mode (GCM)
A128GCM
http://www.w3.org/2009/xmlenc11#aes128-gcm
AES/GCM/NoPadding
Advanced Encryption Standard (AES) using 256 bit keys in
Galois/Counter Mode (GCM)
A256GCM
http://www.w3.org/2009/xmlenc11#aes256-gcm
AES/GCM/NoPadding
Solutions for signing and encrypting JSON content were
previously explored by Magic
Signatures, JSON Simple Sign,
Canvas Applications, JSON Simple Encryption, and JavaScript Message Security
Format, all of which influenced this draft. Dirk
Balfanz, John Bradley, Yaron Y. Goland, John Panzer, Nat
Sakimura, and Paul Tarjan all made significant contributions
to the design of this specification and its related
specifications.
-02
For AES GCM,
use the "additional authenticated data" parameter
to provide integrity for the header, encrypted key, and
ciphertext and use the resulting "authentication tag"
value as the JWE Integrity Value.
Defined minimum required key sizes for algorithms
without specified key sizes.
Defined KDF output key sizes.
Specified the use of PKCS #5 padding with AES-CBC.
Generalized text to allow key agreement to be employed
as an alternative to key wrapping or key encryption.
Clarified that ECDH-ES is a key agreement algorithm.
Required implementation of AES-128-KW and AES-256-KW.
Removed the use of A128GCM and
A256GCM for key wrapping.
Removed A512KW since it turns
out that it's not a standard algorithm.
Clarified the relationship between
typ header parameter values
and MIME types.
Generalized language to refer to Message Authentication Codes (MACs)
rather than Hash-based Message Authentication Codes (HMACs)
unless in a context specific to HMAC algorithms.
Established registries:
JSON Web Signature and Encryption Header Parameters,
JSON Web Signature and Encryption Algorithms,
JSON Web Signature and Encryption "typ" Values,
JSON Web Key Parameters, and
JSON Web Key Algorithm Families.
Moved algorithm-specific definitions from JWK to JWA.
Reformatted to give each member definition its own section heading.

-01
Moved definition of "alg":"none" for JWSs here from the JWT
specification since this functionality is likely to be
useful in more contexts that just for JWTs.
Added Advanced Encryption Standard (AES) Key Wrap Algorithm
using 512 bit keys (A512KW).
Added text "Alternatively, the Encoded JWS Signature MAY be base64url
decoded to produce the JWS Signature and this value can
be compared with the computed HMAC value, as this
comparison produces the same result as comparing the
encoded values".
Corrected the Magic Signatures reference.
Made other editorial improvements suggested by JOSE
working group participants.

-00
Created the initial IETF draft based upon
draft-jones-json-web-signature-04 and
draft-jones-json-web-encryption-02 with no normative changes.
Changed terminology to no longer call both digital
signatures and HMACs "signatures".