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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 INTERNET-DRAFT Simon Blake-Wilson, Certicom Corp 2 draft-ietf-smime-ecc-02.txt Daniel R. L. Brown, Certicom Corp 3 7 September, 2000 Expires: 7 March, 2001 5 Use of ECC Algorithms in CMS 7 Status of this Memo 9 This document is an Internet-Draft and is in full conformance with 10 all provisions of Section 10 of RFC2026. Internet-Drafts are 11 working documents of the Internet Engineering Task Force (IETF), 12 its areas, and its working groups. Note that other groups may also 13 distribute working documents as Internet-Drafts. 15 Internet-Drafts are draft documents valid for a maximum of six 16 months and may be updated, replaced, or obsoleted by other 17 documents at any time. It is inappropriate to use Internet-Drafts 18 as reference material or to cite them other than as "work in 19 progress." 21 The list of current Internet-Drafts can be accessed at 22 http://www.ietf.org/ietf/1id-abstracts.txt 24 The list of Internet-Draft Shadow Directories can be accessed at 25 http://www.ietf.org/shadow.html. 27 Abstract 29 This document describes how to use Elliptic Curve Cryptography 30 (ECC) public-key algorithms in the Cryptographic Message Syntax 31 (CMS). The ECC algorithms support the creation of digital 32 signatures and the exchange of keys to encrypt or authenticate 33 content. The definition of the algorithm processing is based on 34 the ANSI X9.62 standard and the ANSI X9.63 draft, developed by the 35 ANSI X9F1 working group. 37 Table of Contents 39 1 Introduction ........................................ 3 40 1.1 Requirement terminology ........................ 3 41 2 SignedData using ECC ................................ 3 42 2.1 SignedData using ECDSA ......................... 3 43 2.1.1 Fields of the SignedData ................ 3 44 2.1.2 Actions of the sending agent ............ 4 45 2.1.3 Actions of the receiving agent .......... 4 46 3 EnvelopedData using ECC ............................. 5 47 3.1 EnvelopedData using ECDH ....................... 5 48 3.1.1 Fields of KeyAgreeRecipientInfo ......... 5 49 3.1.2 Actions of the sending agent ............ 5 50 3.1.3 Actions of the receiving agent .......... 6 51 3.2 EnvelopedData using 1-Pass ECMQV ............... 6 52 3.2.1 Fields of KeyAgreeRecipientInfo ......... 6 53 3.2.2 Actions of the sending agent ............ 7 54 3.2.3 Actions of the receiving agent .......... 8 55 4 AuthenticatedData using ECC ............ ............ 8 56 4.1 AuthenticatedData using 1-pass ECMQV ........... 8 57 4.1.1 Fields of KeyAgreeRecipientInfo ......... 8 58 4.1.2 Actions of the sending agent ............ 8 59 4.1.3 Actions of the receiving agent .......... 9 60 5 Recommended Elliptic Curves ......................... 9 61 6 Certificates using ECC .............................. 9 62 7 SMIMECapabilities Attribute and ECC ................. 9 63 8 ASN.1 Syntax ........................................ 9 64 8.1 Algorithm identifiers .......................... 9 65 8.2 Other syntax ................................... 11 66 9 Summary ............................................. 12 67 References ............................................. 12 68 Security Considerations ................................ 14 69 Intellectual Property Rights ........................... 14 70 Acknowledgments ........................................ 14 71 Authors' Address ....................................... 14 72 Full Copyright Statement ............................... 15 74 1 Introduction 76 The Cryptographic Message Syntax (CMS) is cryptographic algorithm 77 independent. This specification defines a standard profile for the 78 use of Elliptic Curve Cryptography (ECC) public key algorithms in 79 the CMS. The ECC algorithms are incorporated into the following 80 CMS content types: 82 - 'SignedData' to support ECC-based digital signature methods 83 (ECDSA) to sign content 85 - 'EnvelopedData' to support ECC-based public-key agreement 86 methods (ECDH and ECMQV) to generate pairwise key-encryption 87 keys to encrypt content-encryption keys used for content 88 encryption 90 - 'AuthenticatedData' to support ECC-based public-key agreement 91 methods (ECMQV) to generate pairwise key-encryption keys to 92 encrypt MAC keys used for content authentication 94 Certification of EC public keys is also described to provide 95 public-key distribution in support of the specified techniques. 97 1.1 Requirements terminology 99 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 100 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 101 this document are to be interpreted as described in RFC 2119 102 [MUST]. 104 2 SignedData using ECC 106 This section describes how to use ECC algorithms with the CMS 107 SignedData format to sign data. 109 2.1 SignedData using ECDSA 111 This section describes how to use the Elliptic Curve Digital 112 Signature Algorithm (ECDSA) with SignedData. ECDSA is specified in 113 [X9.62]. The method is the elliptic curve analog of the 114 Digital Signature Algorithm (DSA) [FIPS 186-2]. 116 2.1.1 Fields of the SignedData 118 When using ECDSA with SignedData the fields of SignerInfo are as in 119 [CMS], but with the following restrictions: 121 digestAlgorithm contains the algorithm identifier sha-1 (see 122 Section 8.1) which identifies the SHA-1 hash algorithm. 124 signatureAlgorithm contains the algorithm identifier 125 ecdsa-with-SHA1 (see Section 8.1) which identifies the ECDSA 126 signature algorithm. 128 signature contains the DER encoding (as an octet string) of a 129 value of the ASN.1 type ECDSA-Sig-Value (see Section 130 7.2). 132 When using ECDSA, the SignedData certificates field may include the 133 certificate(s) for the EC public key(s) used in the generation of 134 the ECDSA signatures in SignedData. ECC certificates are discussed 135 in Section 6. 137 2.1.2 Actions of the sending agent 139 When using ECDSA with SignedData, the sending agent uses the 140 message digest calculation process and signature generation process 141 for SignedData that are specified in [CMS]. To sign data, the 142 sending agent uses the signature method specified in [X9.62, 143 Section 5.3] with the following exceptions: 145 - In [X9.62, Section 5.3.1], the integer "e" shall instead be 146 determined by converting the octet string resulting from [CMS, 147 Section 5.4] to an integer using the data conversion method in 148 [X9.62, Section 4.3.2]. 150 The sending agent encodes the resulting signature using the 151 ECDSA-sig-value syntax and places it in the SignerInfo signature 152 field. 154 2.1.3 Actions of the receiving agent 156 When using ECDSA with SignedData, the receiving agent uses the 157 message digest calculation process and signature verification 158 process for SignedData that are specified in [CMS]. To verify 159 SignedData, the receiving agent uses the signature verification 160 method specified in [X9.62, Section 5.4] with the following 161 exceptions: 163 - In [X9.62, Section 5.4.1] the integer "e" shall instead be 164 determined by converting the octet string resulting from [CMS, 165 Section 5.4] to an integer using the data conversion method in 166 [X9.62, Section 4.3.2]. 168 In order to verify the signature, the receiving agent retrieves the 169 integers r and s from the SignerInfo signature field of the 170 received message. 172 3 EnvelopedData using ECC Algorithms 174 This section describes how to use ECC algorithms with the CMS 175 EnvelopedData format. 177 3.1 EnvelopedData using (ephemeral-static) ECDH 179 This section describes how to use ephemeral-static Elliptic Curve 180 Diffie-Hellman (ECDH) key agreement algorithm with EnvelopedData. 181 Ephemeral-static ECDH is specified in [X9.63]. Ephemeral-static 182 ECDH is the the elliptic curve analog of the ephemeral-static 183 Diffie-Hellman key agreement algorithm specified jointly in the 184 documents [CMS, Section 12.3.1.1] and [CMS-DH]. 186 3.1.1 Fields of KeyAgreeRecipientInfo 188 When using ephemeral-static ECDH with EnvelopedData, the fields of 189 KeyAgreeRecipientInfo are as in [CMS], but with the following 190 restrictions: 192 originator is the alternative originatorKey. The originatorKey 193 algorithm field contains the id-ecPublicKey object identifier 194 (see Section 8.1) with NULL parameters. The originatorKey 195 publicKey field contains the DER-encoding of a value of the 196 ASN.1 type ECPoint (see Section 8.2). 198 keyEncryptionAlgorithm contains the 199 dhSinglePass-stdDH-sha1kdf-scheme object identifier (see Section 200 7.1) if standard ECDH primitive is used, or the 201 dhSinglePass-cofactorDH-sha1kdf-scheme object identifier (see 202 Section 8.1) if the cofactor ECDH primitive is used. The 203 parameter field contains KeyWrapAlgorithm. The KeyWrapAlgorithm 204 is the algorithm identifier that indicates the symmetric 205 encryption algorithm used to encrypt the CEK with the KEK. 207 3.1.2 Actions of the sending agent 209 When using ephemeral-static ECDH with EnvelopedData, the sending 210 agent first obtains the recipient's EC public key and domain 211 parameters (e.g. from the recipient's certificate). The sending 212 agent then determines an integer "keydatalen" which is the 213 key-size, in bits, of the KeyWrapAlgorithm and a bit string 214 "SharedData". The "SharedData" bit string is the DER encoding of 215 ASN.1 type X9-63-CMS-SharedInfo (see Section 8.2). The sending 216 agent then performs the initiator transformation of the 1-Pass 217 Diffie-Hellman scheme specified in [X9.63, Section 6.2.1]. As a 218 result the sending agent obtains: 220 - an ephemeral public key, which is represented as a value of 221 the type ECPoint (see Section 8.2), encapsulated in a bit 222 string and placed in the KeyAgreeRecipientInfo originator 223 field, and 225 - a shared secret bit string "KeyData" which is used as the 226 pairwise key-encryption key for that recipient. 228 3.1.3 Actions of the receiving agent 230 When using ephemeral-static ECDH with EnvelopedData, the receiving 231 agent determines the bit string "SharedData" (see Section 8.2) and 232 the integer "keydatalen" from the key-size, in bits, of the 233 KeyWrapAlgorithm. The receiving agent retrieves the ephemeral EC 234 public key from the bit string KeyAgreeRecipientInfo originator, 235 which an value of the type ECPoint (see Section 8.2) encapsulated 236 as a bit string. The receiving agent completes the responder 237 transformation of the 1-Pass Diffie-Hellman scheme [X9.63, Section 238 6.2.2]. As a result the receiving agent obtains a shared secret 239 bit string "KeyData" which is used as the pairwise key-encryption 240 key to unwrap the CEK. 242 3.2 EnvelopedData using 1-Pass ECMQV 244 This section describes how to use the 1-Pass elliptic curve MQV 245 (ECMQV) key agreement algorithm with EnvelopedData. 1-Pass ECMQV 246 is specified in [X9.63]. Like the KEA algorithm [CMS-KEA], 1-Pass 247 ECMQV uses three key pairs: an ephemeral key pair, a static key 248 pair of the sending agent, and a static key pair of the receiving 249 agent. An advantage of using 1-Pass ECMQV is that it may be used 250 with both EnvelopedData and AuthenticatedData. 252 3.2.1 Fields of KeyAgreeRecipientInfo 254 When using 1-Pass ECMQV with EnvelopedData the fields of 255 KeyAgreeRecipientInfo are: 257 version is 3 259 originator identifies the static EC public key of the sender. 260 It should be the one of the alternatives issuerAndSerialNumber 261 or subjectKeyIdentifier and point to one of the sending agent's 262 certificates supplied in the EnvelopedData originatorInfo field. 264 ukm is present. The ukm field contains an octet string which is 265 the DER encoding of the type MQVuserKeyingMaterial (see Section 266 8.2). The MQVuserKeyingMaterial ephemeralPublicKey algorithm 267 field contains the id-ecPublicKey object identifier (see Section 268 8.1) with NULL parameters field. The MQVuserKeyingMaterial 269 ephemeralPublicKey publicKey field contains the DER-encoding of 270 the ASN.1 type ECPoint representing sending agent's ephemeral EC 271 public key. The MQVuserKeyingMaterial addedukm field, if 272 present, contains an octet string of additional user keying 273 material of the sending agent. 275 keyEncryptionAlgorithm is the mqvSinglePass-sha1kdf-scheme 276 algorithm identifier (see Section 8.1), with parameter field 277 KeyWrapAlgorithm. The KeyWrapAlgorithm indicates the symmetric 278 encryption algorithm used to encrypt the CEK with the KEK 279 generated using the 1-Pass ECMQV algorithm. 281 3.2.2 Actions of the sending agent 283 When using 1-Pass ECMQV with EnvelopedData, the sending agent first 284 obtains the recipient's EC public key and domain parameters, 285 (e.g. from the recipient's certificate) and checks that the domain 286 parameters are the same. The sending agent then determines an 287 integer "keydatalen" which is the key-size, in bits, of the 288 KeyWrapAlgorithm and a bit string "SharedData" (see Section 8.2). 289 The sending agent then performs the initiator transformation of the 290 1-Pass ECMQV scheme specified in [X9.63, Section 6.9.1]. As a 291 result the sending agent obtains 293 - an ephemeral public key, which is represented as a value of 294 type ECPoint (see Section 8.2), encapsulated in a bit string, 295 placed in an MQVuserKeyingMaterial ephemeralPublicKey 296 publicKey field (see Section 8.2), and 298 - a shared secret bit string "KeyData" which is used as the 299 pairwise key-encryption key for that recipient. Parity bits 300 are adjust according to the key wrap algorithm. 302 The ephemeral public key may be re-used with an AuthenticatedData 303 for greater efficiency. 305 3.2.3 Actions of the receiving agent 307 When using 1-Pass ECMQV with EnvelopedData, the receiving agent 308 determines the bit string "SharedData" (see Section 8.2) and the 309 integer "keydatalen" from the key-size, in bits, of the 310 KeyWrapAlgorithm. The receiving agent then retrieves the static 311 and ephemeral EC public keys of the originator, from the originator 312 and ukm fields as described in Section 3.2.1, and its static EC 313 public key identified in the rid field and checks that the domain 314 parameters are the same. The receiving agent then performs the 315 responder transformation of the 1-Pass ECMQV scheme [X9.63, Section 316 6.9.2]. As a result the receiving agent obtains a shared secret 317 bit string "KeyData" which is used as the pairwise key-encryption 318 key to unwrap the CEK. 320 4 AuthenticatedData using ECC 322 This section describes how to use ECC algorithms with the CMS 323 AuthenticatedData format. AuthenticatedData lacks non-repudiation, 324 and so in some instances is preferrable SignedData. (For example, 325 the sending agent may not want the message to be authenticated when 326 forwarded.) 328 4.1 AuthenticatedData using 1-pass ECMQV 330 This section describes how to use the 1-Pass elliptic curve MQV 331 (ECMQV) key agreement algorithm with AuthenticatedData. 1-Pass 332 ECMQV is specified in [X9.63]. An advantage of using 1-Pass ECMQV 333 is that it may be used with both EnvelopedData and 334 AuthenticatedData. 336 4.1.1 Fields of the KeyAgreeRecipientInfo 338 The AuthenticatedData KeyAgreeRecipientInfo fields are used in the 339 same manner as the fields for the corresponding EnvelopedData 340 KeyAgreeRecipientInfo fields of Section 3.2.1 of this document. 342 4.1.2 Actions of the sending agent 344 The sending agent uses the same actions as for EnvelopedData 345 with 1-Pass ECMQV, as specified in Section 3.2.2 of this document. 347 The ephemeral public key may be re-used with an EnvelopedData for 348 greater efficiency. 350 Note: if there are multiple recipients then an attack is possible 351 where one recipient modifies the content without other recipients 352 noticing [BON]. A sending agent who is concerned with such an 353 attack should use a separate AuthenticatedData for each recipient. 355 4.1.3 Actions of the receiving agent 357 The receiving agent uses the same actions as for EnvelopedData 358 with 1-Pass ECMQV, as specified in Section 3.2.3 of this document. 360 Note: see Note in Section 4.1.2. 362 5 Recommended Elliptic Curves 364 It is strongly recommended that agents use the elliptic curve 365 domain parameters recommended by ANSI [X9.62, X9.63], NIST [REC-EC] 366 and SECG [SEC3]. 368 6 Certificates using ECC 370 Internet X.509 certificates [PKI] may be used in conjunction with 371 this specification to distribute agents' public keys. The use of 372 ECC algorithms and keys within X.509 certificates is specified in 373 [PKI-ALG]. More details can be found in [SEC3]. 375 7 SMIMECapabilities Attribute and ECC 377 A sending agent may choose to announce to receiving agents that it 378 supports one or more of the ECC algorithms in this document by 379 using the SMIMECapabilities signed attribute [MSG, Section 2.5.2]. 381 The SMIMECapability value to indicate support for the ECDSA 382 signature algorithm is the SEQUENCE with the capabilityID field 383 containing the object identifier ecdsa-with-SHA1 with NULL 384 parameters. 386 The SMIMECapability capabilityID object identifiers for the 387 supported key agreement algorithms in this document are 388 dhSinglePass-stdDH-sha1kdf-scheme, 389 dhSinglePass-cofactorDH-sha1kdf-scheme, and 390 mqvSinglePass-sha1kdf-scheme. For each of these SMIMECapability 391 SEQUENCEs the parameters field is present and indicates the 392 supported key-encryption algorithm with the KeyWrapAlgorithm 393 algorithm identifier. 395 8 ASN.1 Syntax 397 The ASN.1 syntax that is used in this document is gathered together 398 in this section for reference purposes. 400 8.1 Algorithm identifiers 402 The algorithm identifiers used in this document are taken from 403 [X9.62] and [X9.63]. 405 The following object identifier indicates the hash algorithm used 406 in this document: 408 sha-1 OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) 409 oiw(14) secsig(3) algorithm(2) 26 } 411 The following object identifier is used in this document to 412 indicate an elliptic curve public key: 414 id-ecPublicKey OBJECT IDENTIFIER ::= { ansi-x9-62 keyType(2) 1 } 416 where 418 ansi-x9-62 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) 419 10045 } 421 When the object identifier id-ecPublicKey is used here with an 422 algorithm identifier, the associated parameters contain NULL. 424 The following object identifier indicates the digital signature 425 algorithm used in this document: 427 ecdsa-with-SHA1 OBJECT IDENTIFIER ::= { ansi-x9-62 signatures(4) 428 1 } 430 When the object identifier ecdsa-with-SHA1 is used within an 431 algorithm identifier, the associated parameters field contains 432 NULL. 434 The following object identifiers indicate the key agreement 435 algorithms used in this document: 437 dhSinglePass-stdDH-sha1kdf-scheme OBJECT IDENTIFIER ::= { 438 x9-63-scheme 2} 440 dhSinglePass-cofactorDH-sha1kdf-scheme OBJECT IDENTIFIER ::= { 441 x9-63-scheme 3} 443 mqvSinglePass-sha1kdf-scheme OBJECT IDENTIFIER ::= { 444 x9-63-scheme 16} 446 where 448 x9-63-scheme OBJECT IDENTIFIER ::= { iso(1) 449 identified-organization(3) tc68(133) country(16) x9(840) 450 x9-63(63) schemes(0) } 452 When the object identifiers are used here within an algorithm 453 identifier, the associated parameters field contains the CMS 454 KeyWrapAlgorithm algorithm identifier. 456 8.2 Other syntax 458 The following additional syntax is used here. 460 When using ECDSA with SignedData, ECDSA signatures are encoded 461 using the type: 463 ECDSA-Sig-Value ::= SEQUENCE { 464 r INTEGER, 465 s INTEGER } 467 ECDSA-Sig-Value is specified in [X9.62]. Within CMS, 468 ECDSA-Sig-Value is DER-encoded and placed within a signature field 469 of SignedData. 471 When using ECDH and ECMQV with EnvelopedData and AuthenticatedData, 472 ephemeral and static public keys are encoded using the type 473 ECPoint. 475 ECPoint ::= OCTET STRING 477 When using ECQMV with EnvelopedData and AuthenticatedData, the 478 sending agent's ephemeral public key and additional keying material 479 are encoded using the type: 481 MQVuserKeyingMaterial ::= SEQUENCE { 482 ephemeralPublicKey OriginatorPublicKey, 483 addedukm [0] EXPLICIT UserKeyingMaterial OPTIONAL } 485 The ECPoint syntax in used to represent the ephemeral public key 486 and placed in the ephemeralPublicKey field. The additional user 487 keying material is place in the addedukm field. Then the 488 MQVuserKeyingMaterial value is DER-encoded and placed within in a 489 ukm field of EnvelopedData or AuthenticatedData. 491 When using ECDH or ECMQV with EnvelopedData or AuthenticatedData, 492 the key-encryption keys are derived by using the type: 494 ECC-CMS-SharedInfo ::= SEQUENCE { 495 keyInfo AlgorithmIdentifier, 496 entityUInfo [0] EXPLICIT OCTET STRING OPTIONAL, 497 suppPubInfo [2] EXPLICIT OCTET STRING } 499 The fields of ECC-63-CMS-SharedInfo are as follows: 501 keyInfo contains the object identifier of the key-encryption 502 algorithm (used to wrap the CEK) and NULL parameters. 504 entityUInfo optionally contains additional keying material 505 supplied by the sending agent. When used with ECDH and CMS, the 506 entityUInfo field contains the octet string ukm. When used with 507 ECMQV and CMS, the entityUInfo contains the octet string 508 addedukm (encoded in MQVuserKeyingMaterial). 510 suppPubInfo contains the length of the generated KEK, in bits, 511 represented as a 32 bit number, as in [CMS-DH]. (E.g. for 3DES 512 it would be 00 00 00 c0.) 514 Within CMS, ECC-CMS-SharedInfo is DER-encoded and used as input to 515 the key derivation function, as specified in [X9.63]. Note that 516 ECC-CMS-SharedInfo differs from the OtherInfo specified in 517 [CMS-DH]. Here a counter value is not included in the keyInfo 518 field because the key derivation function specified in [X9.63] 519 ensures that sufficient keying data is provided. 521 9 Summary 523 This document specifies how to use ECC algorithms with the S/MIME 524 CMS. Use of ECC algorithm within CMS can result in reduced 525 processing requirements for S/MIME agents, and reduced bandwidth 526 for CMS messages. 528 References 530 [X9.42] ANSI X9.42-xxxx, "Agreement Of Symmetric Keys Using 531 Diffie-Hellman and MQV Algorithms", American National 532 Standards Institute, 2000, Working draft. 534 [X9.62] ANSI X9.62-1999, "Public Key Cryptography For The 535 Financial Services Industry: The Elliptic Curve 536 Digital Signature Algorithm (ECDSA)", Americal 537 National Standards Institute, 1999. 539 [X9.63] ANSI X9.63-xzxx, "Public Key Cryptography For The 540 Financial Services Industry: Key Agreement and Key 541 Transport Using Elliptic Curve Cryptography", American 542 National Standards Institute, 1999, Working draft. 544 [PKI-ALG] L. Bassham, R. Housley and W. Polk, "Internet X.509 545 Public Key Infrastructure Representation of Public 546 Keys and Digital Signatures in Internet X.509 Public 547 Key Infrastructure Certificates", PKIX Working Group 548 Internet-Draft, July 2000. 550 [BON] D. Boneh, "The Security of Multicast MAC", 551 Presentation at Selected Areas of Cryptography 2000, 552 Center for Applied Cryptographic Research, University 553 of Waterloo, 2000 555 [MUST] S. Bradner, "Key Words for Use in RFCs to Indicate 556 Requirement Levels", RFC 2119, March 1997. 558 [FIPS-180] FIPS 180-1, "Secure Hash Standard", National Institute 559 of Standards and Technology, April 17, 1995. 561 [FIPS-186-2] FIPS 186-2, "Digital Signature Standard", National 562 Institute of Standards and Technology, 15 February 563 2000. 565 [PKI] W. Ford, R. Housley, W. Polk and D. Solo, "Internet X.509 566 Public Key Infrastructure Certificate and CRL 567 Profile", PKIX Working Group Internet-Draft, July 568 2000. 570 [CMS] R. Housley, "Cryptographic Message Syntax", RFC 2630, 571 June 1999. 573 [IEEE1363] IEEE P1363, "Standard Specifications for Public Key 574 Cryptography", Institute of Electrical and Electronics 575 Engineers, 2000. 577 [LMQSV] L. Law, A. Menezes, M. Qu, J. Solinas and S. Vanstone, 578 "An efficient protocol for authenticated key agreement", 579 Technical report CORR 98-05, University of Waterloo, 580 1998. 582 [REC-EC] National Institute of Standards and Technology, 583 "Recommended Elliptic Curves for Federal Government 584 Use", July, 1999. Available from: 585 . 587 [CMS-KEA] J. Pawling, "CMS KEA and SKIPJACK Conventions", S/MIME 588 Working Group Internet-Draft, December, 1999. 590 [MSG] B. Ramsdell, "S/MIME Version 3 Message Specification", 591 RFC 2633, June 1999. 593 [CMS-DH] E. Rescorla, "Diffie-Hellman Key Agreement Method", 594 RFC 2631, June 1999. 596 [SEC1] SECG, "Elliptic Curve Cryptography", Standards for 597 Efficient Cryptography Group, 2000. 599 [SEC2] SECG, "Recommended Elliptic Curve Domain Parameters", 600 Standards for Efficient Cryptography Group, 2000. 602 [SEC3] SECG, "ECC in X.509", Standards for Efficient 603 Cryptography Group, 2000. 605 Security Considerations 607 This specification is based on [CMS], [X9.62] and [X9.63] and the 608 appropriate security considerations of those documents apply. 610 Intellectual Property Rights 612 The IETF has been notified of intellectual property rights claimed 613 in regard to the specification contained in this document. For 614 more information, consult the online list of claimed rights 615 (http://www.ietf.org/ipr.html). 617 The IETF takes no position regarding the validity or scope of any 618 intellectual property or other rights that might be claimed to 619 pertain to the implementation or use of the technology described in 620 this document or the extent to which any license under such rights 621 might or might not be available; neither does it represent that it 622 has made any effort to identify any such rights. Information on the 623 IETF's procedures with respect to rights in standards-track and 624 standards-related documentation can be found in BCP-11. Copies of 625 claims of rights made available for publication and any assurances 626 of licenses to be made available, or the result of an attempt made 627 to obtain a general license or permission for the use of such 628 proprietary rights by implementors or users of this specification 629 can be obtained from the IETF Secretariat. 631 Acknowledgments 633 The methods described in this document are based on work done by 634 the ANSI X9F1 working group. The authors wish to extend their 635 thanks to ANSI X9F1 for their assistance. 637 The authors also wish to thank Paul Lambert and Peter de Rooij for 638 their patient assistance. 640 Authors' Address 642 Simon Blake-Wilson 643 Certicom Corp 644 5520 Explorer Drive #400 645 Mississauga, ON L4W 5L1 647 EMail: sblakewi@certicom.com 648 Daniel R. L. Brown 649 Certicom Corp 650 5520 Explorer Drive #400 651 Mississauga, ON L4W 5L1 653 EMail: dbrown@certicom.com 655 Full Copyright Statement 657 Copyright (C) The Internet Society (2000). All Rights Reserved. 659 This document and translations of it may be copied and furnished to 660 others, and derivative works that comment on or otherwise explain 661 it or assist in its implementation may be prepared, copied, 662 published and distributed, in whole or in part, without restriction 663 of any kind, provided that the above copyright notice and this 664 paragraph are included on all such copies and derivative works. 665 However, this document itself may not be modified in any way, such 666 as by removing the copyright notice or references to the Internet 667 Society or other Internet organizations, except as needed for the 668 purpose of developing Internet standards in which case the 669 procedures for copyrights defined in the Internet Standards process 670 must be followed, or as required to translate it into languages 671 other than English. 673 The limited permissions granted above are perpetual and will not be 674 revoked by the Internet Society or its successors or assigns. 676 This document and the information contained herein is provided on 677 an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET 678 ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR 679 IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 680 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 681 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.