RFC 3278

Use of Elliptic Curve Cryptography (ECC) Algorithms in Cryptographic Message Syntax (CMS)

๐Ÿ“… published May 2002, from ietf

RFC 3278: Use of Elliptic Curve Cryptography (ECC) Algorithms in Cryptographic Message Syntax (CMS) ๐Ÿ’–

Okay bestie, this one is from April 2002 and it's written by S. Blake-Wilson and D. Brown from Certicom Corp, plus P. Lambert from Cosine Communications ๐ŸŽ€. It's an Informational doc, which means it's giving "here's useful info," not "here's a standard you must follow." It's from the Network Working Group. The title block doesn't say it obsoletes or updates anything, so it's just doing its own thing ๐Ÿฆ‹.


Status of This Memo โœจ

This memo is here to provide information for the Internet community ๐ŸŒธ. It doesn't specify an Internet standard of any kind, and distribution of this memo is unlimited ๐Ÿ’….

Copyright (C) The Internet Society (2002). All Rights Reserved โญ.

Abstract ๐Ÿฆ‹

Okay so this document explains how to use Elliptic Curve Cryptography (ECC) public-key algorithms inside the Cryptographic Message Syntax (CMS) ๐Ÿงš. ECC lets you make digital signatures and swap keys so you can encrypt or authenticate content, and it's literally iconic ๐Ÿ‘‘. The algorithm processing is based on the ANSI X9.62 standard (made by the ANSI X9F1 working group), the IEEE 1363 standard, and the SEC 1 standard ๐Ÿ“š.

The readers attention is called to the Intellectual Property Rights section at the end of this document ๐Ÿซถ.

Table of Contents ๐Ÿ“

1  Introduction ................................................... 2
   1.1  Requirements terminology .................................. 3
2  SignedData using ECC ..........................................  3
   2.1  SignedData using ECDSA ...................................  3
        2.1.1  Fields of the SignedData ..........................  3
        2.1.2  Actions of the sending agent ......................  4
        2.1.3  Actions of the receiving agent ....................  4
3  EnvelopedData using ECC .......................................  4
   3.1  EnvelopedData using ECDH .................................  5
        3.1.1  Fields of KeyAgreeRecipientInfo ...................  5
        3.1.2  Actions of the sending agent ......................  5
        3.1.3  Actions of the receiving agent ....................  6
   3.2  EnvelopedData using 1-Pass ECMQV .........................  6
        3.2.1  Fields of KeyAgreeRecipientInfo ...................  6
        3.2.2  Actions of the sending agent ......................  7
        3.2.3  Actions of the receiving agent ....................  7
4  AuthenticatedData using ECC ............ ......................  8
   4.1  AuthenticatedData using 1-pass ECMQV .....................  8
        4.1.1  Fields of KeyAgreeRecipientInfo ...................  8
        4.1.2  Actions of the sending agent ......................  8
        4.1.3  Actions of the receiving agent ....................  8
5  Recommended Algorithms and Elliptic Curves ....................  9
6  Certificates using ECC ........................................  9
7  SMIMECapabilities Attribute and ECC ...........................  9
8  ASN.1 Syntax .................................................. 10
   8.1  Algorithm identifiers .................................... 10
   8.2  Other syntax ............................................. 11
9  Summary ....................................................... 12
References ....................................................... 13
Security Considerations .......................................... 14
Intellectual Property Rights ..................................... 14
Acknowledgments .................................................. 15
Authors' Addresses ............................................... 15
Full Copyright Statement ......................................... 16

1. Introduction ๐ŸŒˆ

The Cryptographic Message Syntax (CMS) doesn't care which cryptographic algorithm you use, and that's the vibe ๐Ÿ’œ. This spec is a profile (basically a set of rules) for using ECC public key algorithms in CMS ๐ŸŽ€. ECC gets plugged into three CMS content types:

  • SignedData for ECC-based digital signatures (ECDSA) to sign content โœ๏ธ
  • EnvelopedData for ECC-based public-key agreement (ECDH and ECMQV) to make pairwise key-encryption keys, which then encrypt content-encryption keys used for content encryption ๐Ÿ”
  • AuthenticatedData for ECC-based public-key agreement (ECMQV) to make pairwise key-encryption keys, which then encrypt MAC keys used for content authentication and integrity ๐Ÿ›ก๏ธ

It also covers certification of EC public keys, so people can distribute those keys and the techniques above actually work ๐Ÿงš.

1.1. Requirements terminology ๐Ÿ”ฅ

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 BCP 14, RFC 2119 [MUST] ๐Ÿ’….

2. SignedData using ECC โœจ

This section is all about using ECC algorithms with the CMS SignedData format to sign data ๐Ÿฆ‹.

2.1. SignedData using ECDSA ๐ŸŒธ

This section covers using the Elliptic Curve Digital Signature Algorithm (ECDSA) with SignedData ๐Ÿ’–. ECDSA is specified in [X9.62]. It's the elliptic curve version of the Digital Signature Algorithm (DSA) [FIPS 186-2], so if you know DSA you're already halfway there ๐Ÿง .

In an implementation that uses ECDSA with CMS SignedData, the following techniques and formats MUST be used ๐Ÿ‘‘.

2.1.1. Fields of the SignedData ๐ŸŽ€

When you use ECDSA with SignedData, the fields of SignerInfo are the same as in [CMS], with these restrictions ๐Ÿซถ:

  • digestAlgorithm MUST contain the algorithm identifier sha-1 (see Section 8.1), which identifies the SHA-1 hash algorithm.
  • signatureAlgorithm contains the algorithm identifier ecdsa-with-SHA1 (see Section 8.1), which identifies the ECDSA signature algorithm.
  • signature MUST contain the DER encoding (as an octet string) of a value of the ASN.1 type ECDSA-Sig-Value (see Section 8.2).

When using ECDSA, the SignedData certificates field MAY include the certificate(s) for the EC public key(s) used to generate the ECDSA signatures in SignedData ๐ŸŒŸ. ECC certificates are discussed in Section 6 ๐Ÿ“.

2.1.2. Actions of the sending agent ๐Ÿฆ‹

When using ECDSA with SignedData, the sending agent uses the message digest calculation process and signature generation process for SignedData that are specified in [CMS] ๐Ÿงš. To sign data, the sending agent uses the signature method specified in [X9.62, Section 5.3], with this one exception ๐Ÿ’œ:

  • In [X9.62, Section 5.3.1], the integer "e" is instead determined by converting the message digest generated according to [CMS, Section 5.4] to an integer, using the data conversion method in [X9.62, Section 4.3.2].

The sending agent encodes the resulting signature using the ECDSA-Sig-Value syntax (see Section 8.2) and puts it in the SignerInfo signature field ๐ŸŽ€.

2.1.3. Actions of the receiving agent ๐ŸŒˆ

When using ECDSA with SignedData, the receiving agent uses the message digest calculation process and signature verification process for SignedData that are specified in [CMS] ๐Ÿ”. To verify SignedData, the receiving agent uses the signature verification method specified in [X9.62, Section 5.4], with this one exception โญ:

  • In [X9.62, Section 5.4.1], the integer "e'" is instead determined by converting the message digest generated according to [CMS, Section 5.4] to an integer, using the data conversion method in [X9.62, Section 4.3.2].

To verify the signature, the receiving agent pulls the integers r and s out of the SignerInfo signature field of the received message ๐Ÿ™ˆ.

3. EnvelopedData using ECC Algorithms ๐Ÿงš

This section covers using ECC algorithms with the CMS EnvelopedData format ๐Ÿ’–.

3.1. EnvelopedData using (ephemeral-static) ECDH ๐Ÿ’œ

This section covers the ephemeral-static Elliptic Curve Diffie-Hellman (ECDH) key agreement algorithm with EnvelopedData ๐Ÿ”ฅ. Ephemeral-static ECDH is specified in [SEC1] and [IEEE1363]. It's the elliptic curve version of the ephemeral-static Diffie-Hellman key agreement algorithm, which is specified jointly in [CMS, Section 12.3.1.1] and [CMS-DH] ๐Ÿฆ‹.

In an implementation that uses ECDH with CMS EnvelopedData and key agreement, the following techniques and formats MUST be used ๐Ÿ‘‘.

3.1.1. Fields of KeyAgreeRecipientInfo ๐ŸŽ€

When you use ephemeral-static ECDH with EnvelopedData, the fields of KeyAgreeRecipientInfo are the same as in [CMS], with these restrictions ๐Ÿซถ:

  • originator MUST be the alternative originatorKey. The originatorKey algorithm field MUST contain the id-ecPublicKey object identifier (see Section 8.1) with NULL parameters. The originatorKey publicKey field MUST contain the DER-encoding of a value of the ASN.1 type ECPoint (see Section 8.2), which represents the sending agent's ephemeral EC public key.
  • keyEncryptionAlgorithm MUST contain the dhSinglePass-stdDH-sha1kdf-scheme object identifier (see Section 8.1) if the standard ECDH primitive is used, or the dhSinglePass-cofactorDH-sha1kdf-scheme object identifier (see Section 8.1) if the cofactor ECDH primitive is used. The parameters field contains KeyWrapAlgorithm. The KeyWrapAlgorithm is the algorithm identifier that indicates the symmetric encryption algorithm used to encrypt the content-encryption key (CEK) with the key-encryption key (KEK) ๐Ÿ”.

3.1.2. Actions of the sending agent ๐ŸŒธ

When using ephemeral-static ECDH with EnvelopedData, the sending agent first gets the recipient's EC public key and domain parameters (for example, from the recipient's certificate) ๐Ÿงš. Then it works out an integer "keydatalen", which is the KeyWrapAlgorithm symmetric key size in bits ๐Ÿ”ข. It also works out a bit string "SharedInfo", which is the DER encoding of ECC-CMS-SharedInfo (see Section 8.2) ๐Ÿ“ฆ. Next, the sending agent does the key deployment and the key agreement operation of the Elliptic Curve Diffie-Hellman Scheme specified in [SEC1, Section 6.1] ๐Ÿ’ซ. As a result, the sending agent gets:

  • an ephemeral public key, which is represented as a value of the type ECPoint (see Section 8.2), encapsulated in a bit string and placed in the KeyAgreeRecipientInfo originator field, and
  • a shared secret bit string "K", which is used as the pairwise key-encryption key for that recipient, as specified in [CMS] ๐Ÿ—๏ธ.

3.1.3. Actions of the receiving agent ๐ŸŒท

When using ephemeral-static ECDH with EnvelopedData, the receiving agent works out the bit string "SharedInfo", which is the DER encoding of ECC-CMS-SharedInfo (see Section 8.2), along with the integer "keydatalen" from the key size in bits of the KeyWrapAlgorithm ๐Ÿงฎ. It gets the ephemeral EC public key out of the KeyAgreeRecipientInfo originator bit string, which holds a value of the type ECPoint (see Section 8.2) encapsulated as a bit string ๐Ÿ”“. Then it does the key agreement operation of the Elliptic Curve Diffie-Hellman Scheme specified in [SEC1, Section 6.1] ๐ŸŒŸ. As a result, the receiving agent gets a shared secret bit string "K", which is used as the pairwise key-encryption key to unwrap the CEK ๐ŸŽ‰.

3.2. EnvelopedData using 1-Pass ECMQV โœจ

okay so this section is about the 1-Pass elliptic curve MQV (ECMQV) key agreement algorithm, used with EnvelopedData ๐Ÿ’…. ECMQV is specified in [SEC1] and [IEEE1363]. Like the KEA algorithm [CMS-KEA], 1-Pass ECMQV uses three key pairs: an ephemeral key pair, a static key pair of the sending agent, and a static key pair of the receiving agent ๐Ÿ”‘. The bestie perk is that 1-Pass ECMQV can be used with both EnvelopedData and AuthenticatedData ๐Ÿฆ‹.

In an implementation that uses 1-Pass ECMQV with CMS EnvelopedData with key agreement, the following techniques and formats MUST be used ๐Ÿซถ.

3.2.1. Fields of KeyAgreeRecipientInfo ๐ŸŽ€

When you use 1-Pass ECMQV with EnvelopedData, the fields of KeyAgreeRecipientInfo are:

originator identifies the static EC public key of the sender ๐Ÿงš. It SHOULD be one of the alternatives, issuerAndSerialNumber or subjectKeyIdentifier, and point to one of the sending agent's certificates.

ukm MUST be present ๐ŸŒธ. The ukm field MUST contain an octet string, which is the DER encoding of the type MQVuserKeyingMaterial (see Section 8.2). The MQVuserKeyingMaterial ephemeralPublicKey algorithm field MUST contain the id-ecPublicKey object identifier (see Section 8.1) with NULL parameters field. The MQVuserKeyingMaterial ephemeralPublicKey publicKey field MUST contain the DER-encoding of the ASN.1 type ECPoint (see Section 8.2), representing the sending agent's ephemeral EC public key ๐Ÿ”ฅ. The MQVuserKeyingMaterial addedukm field, if present, SHOULD contain an octet string of additional user keying material of the sending agent.

keyEncryptionAlgorithm MUST be the mqvSinglePass-sha1kdf-scheme algorithm identifier (see Section 8.1), with the parameters field KeyWrapAlgorithm ๐Ÿ’–. The KeyWrapAlgorithm indicates the symmetric encryption algorithm used to encrypt the CEK with the KEK generated using the 1-Pass ECMQV algorithm.

3.2.2. Actions of the sending agent ๐Ÿ’Œ

When you use 1-Pass ECMQV with EnvelopedData, the sending agent first obtains the recipient's EC public key and domain parameters (e.g. from the recipient's certificate) and checks that the domain parameters are the same ๐Ÿ‘€. Then it determines an integer "keydatalen", which is the KeyWrapAlgorithm symmetric key-size in bits, and also a bit string "SharedInfo", which is the DER encoding of ECC-CMS-SharedInfo (see Section 8.2) โœจ. Next, the sending agent performs the key deployment and key agreement operations of the Elliptic Curve MQV Scheme specified in [SEC1, Section 6.2]. As a result, the sending agent obtains:

  • an ephemeral public key, which is represented as a value of type ECPoint (see Section 8.2), encapsulated in a bit string, placed in an MQVuserKeyingMaterial ephemeralPublicKey publicKey field (see Section 8.2), and
  • a shared secret bit string "K", which is used as the pairwise key-encryption key for that recipient, as specified in [CMS] ๐ŸŒˆ.

The ephemeral public key can be re-used with an AuthenticatedData for greater efficiency โญ.

3.2.3. Actions of the receiving agent ๐Ÿ“

When you use 1-Pass ECMQV with EnvelopedData, the receiving agent determines the bit string "SharedInfo", which is the DER encoding of ECC-CMS-SharedInfo (see Section 8.2), and the integer "keydatalen" from the key-size, in bits, of the KeyWrapAlgorithm ๐Ÿง. It then retrieves the static and ephemeral EC public keys of the originator, from the originator and ukm fields as described in Section 3.2.1, plus its own static EC public key identified in the rid field, and checks that the domain parameters are the same ๐Ÿฆ‹. Then it performs the key agreement operation of the Elliptic Curve MQV Scheme [SEC1, Section 6.2]. As a result, the receiving agent obtains a shared secret bit string "K", which is used as the pairwise key-encryption key to unwrap the CEK ๐Ÿ”“.


4. AuthenticatedData using ECC ๐ŸŒท

okay this section is all about using ECC algorithms with the CMS AuthenticatedData format ๐Ÿ’œ. AuthenticatedData lacks non-repudiation, so in some situations it's preferable to SignedData ๐Ÿ™ˆ. (For example, the sending agent might not want the message to be authenticated when forwarded.)

4.1. AuthenticatedData using 1-pass ECMQV ๐ŸŽ€

This section describes how to use the 1-Pass elliptic curve MQV (ECMQV) key agreement algorithm with AuthenticatedData ๐Ÿ’…. ECMQV is specified in [SEC1]. The big perk of 1-Pass ECMQV is that it can be used with both EnvelopedData and AuthenticatedData, same as before โœจ.

4.1.1. Fields of the KeyAgreeRecipientInfo ๐Ÿงš

The AuthenticatedData KeyAgreeRecipientInfo fields are used in the same manner as the fields for the corresponding EnvelopedData KeyAgreeRecipientInfo fields of Section 3.2.1 of this document ๐Ÿซถ.

4.1.2. Actions of the sending agent ๐ŸŒธ

The sending agent uses the same actions as for EnvelopedData with 1-Pass ECMQV, as specified in Section 3.2.2 of this document ๐Ÿ”ฅ.

The ephemeral public key can be re-used with an EnvelopedData for greater efficiency ๐Ÿ’–.

Note: if there are multiple recipients, an attack is possible where one recipient modifies the content without other recipients noticing [BON] ๐Ÿ’€. A sending agent who is concerned with such an attack SHOULD use a separate AuthenticatedData for each recipient ๐Ÿ›ก๏ธ.

4.1.3. Actions of the receiving agent ๐Ÿ“

The receiving agent uses the same actions as for EnvelopedData with 1-Pass ECMQV, as specified in Section 3.2.3 of this document ๐Ÿง.

Note: see Note in Section 4.1.2.


Implementations of this specification MUST implement either SignedData with ECDSA or EnvelopedData with ephemeral-static ECDH ๐Ÿ”‘. Implementations of this specification SHOULD implement both SignedData with ECDSA and EnvelopedData with ephemeral-static ECDH ๐ŸŒˆ. Implementations MAY implement the other techniques specified, such as AuthenticatedData and 1-Pass ECMQV โญ.

Furthermore, in order to encourage interoperability, implementations SHOULD use the elliptic curve domain parameters specified by ANSI [X9.62], NIST [FIPS-186-2] and SECG [SEC2] ๐Ÿค.

6. Certificates using ECC ๐Ÿ“œ

Internet X.509 certificates [PKI] can be used in conjunction with this specification to distribute agents' public keys ๐ŸŽ€. The use of ECC algorithms and keys within X.509 certificates is specified in [PKI-ALG] ๐Ÿ’….

7. SMIMECapabilities Attribute and ECC ๐Ÿฆ‹

A sending agent MAY announce to receiving agents that it supports one or more of the ECC algorithms in this document by using the SMIMECapabilities signed attribute [MSG, Section 2.5.2] ๐Ÿ“ฃ.

The SMIMECapability value to indicate support for the ECDSA signature algorithm is the SEQUENCE with the capabilityID field containing the object identifier ecdsa-with-SHA1 with NULL parameters. The DER encoding is:

30 0b 06 07  2a 86 48 ce   3d 04 01 05  00

The SMIMECapability capabilityID object identifiers for the supported key agreement algorithms in this document are dhSinglePass-stdDH-sha1kdf-scheme, dhSinglePass-cofactorDH-sha1kdf-scheme, and mqvSinglePass-sha1kdf-scheme ๐ŸŒธ. For each of these SMIMECapability SEQUENCEs, the parameters field is present and indicates the supported key-encryption algorithm with the KeyWrapAlgorithm algorithm identifier. The DER encodings that indicate capability of the three key agreement algorithms with CMS Triple-DES key wrap are:

30 1c 06 09  2b 81 05 10   86 48 3f 00  02 30 0f 06
0b 2a 86 48  86 f7 0d 01   09 10 03 06  05 00

for ephemeral-static ECDH,

30 1c 06 09  2b 81 05 10   86 48 3f 00  03 30 0f 06
0b 2a 86 48  86 f7 0d 01   09 10 03 06  05 00

for ephemeral-static ECDH with cofactor method, and

30 1c 06 09  2b 81 05 10   86 48 3f 00  10 30 0f 06
0b 2a 86 48  86 f7 0d 01   09 10 03 06  05 00

for ECMQV ๐Ÿงš.

8. ASN.1 Syntax ๐Ÿงฎ

The ASN.1 syntax used in this document is gathered in this section for reference purposes ๐Ÿ“š.

8.1. Algorithm identifiers ๐Ÿ”

The algorithm identifiers used in this document are taken from [X9.62], [SEC1] and [SEC2] ๐Ÿ’–.

The following object identifier indicates the hash algorithm used in this document:

sha-1 OBJECT IDENTIFIER ::= { iso(1) identified-organization(3)
   oiw(14) secsig(3) algorithm(2) 26 }

The following object identifier is used in this document to indicate an elliptic curve public key:

id-ecPublicKey OBJECT IDENTIFIER ::= { ansi-x9-62 keyType(2) 1 }

where

ansi-x9-62 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840)
  10045 }

When the object identifier id-ecPublicKey is used here with an algorithm identifier, the associated parameters contain NULL ๐Ÿซถ.

The following object identifier indicates the digital signature algorithm used in this document:

ecdsa-with-SHA1 OBJECT IDENTIFIER ::= { ansi-x9-62 signatures(4)
   1 }

When the object identifier ecdsa-with-SHA1 is used within an algorithm identifier, the associated parameters field contains NULL โœจ.

The following object identifiers indicate the key agreement algorithms used in this document:

dhSinglePass-stdDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
   x9-63-scheme 2}

dhSinglePass-cofactorDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
   x9-63-scheme 3}

mqvSinglePass-sha1kdf-scheme OBJECT IDENTIFIER ::= {
   x9-63-scheme 16}

where

x9-63-scheme OBJECT IDENTIFIER ::= { iso(1)
   identified-organization(3) tc68(133) country(16) x9(840)
   x9-63(63) schemes(0) }

When the object identifiers are used here within an algorithm identifier, the associated parameters field contains the CMS KeyWrapAlgorithm algorithm identifier ๐ŸŒˆ.

8.2. Other syntax

okay so this part is where the ECC bits get their actual outfits ๐Ÿ’… the following extra syntax is used here, and I'm going to show you each piece exactly as it's written so nothing gets lost ๐ŸŽ€

When using ECDSA with SignedData, ECDSA signatures are encoded using the type:

   ECDSA-Sig-Value ::= SEQUENCE {
      r INTEGER,
      s INTEGER }

ECDSA-Sig-Value is specified in [X9.62] ๐Ÿฆ‹ inside CMS it gets DER-encoded and placed within a signature field of SignedData.

When using ECDH and ECMQV with EnvelopedData and AuthenticatedData, ephemeral and static public keys are encoded using the type ECPoint ๐ŸŒธ

   ECPoint ::= OCTET STRING

When using ECMQV with EnvelopedData and AuthenticatedData, the sending agent's ephemeral public key and additional keying material are encoded using the type:

   MQVuserKeyingMaterial ::= SEQUENCE {
      ephemeralPublicKey OriginatorPublicKey,
      addedukm [0] EXPLICIT UserKeyingMaterial OPTIONAL  }

the ECPoint syntax gets used to represent the ephemeral public key, and that goes in the ephemeralPublicKey field ๐Ÿ’– the additional user keying material goes in the addedukm field. then the whole MQVuserKeyingMaterial value gets DER-encoded and placed within a ukm field of EnvelopedData or AuthenticatedData โœจ

When using ECDH or ECMQV with EnvelopedData or AuthenticatedData, the key-encryption keys are derived by using the type:

   ECC-CMS-SharedInfo ::= SEQUENCE {
      keyInfo AlgorithmIdentifier,
      entityUInfo [0] EXPLICIT OCTET STRING OPTIONAL,
      suppPubInfo [2] EXPLICIT OCTET STRING   }

here's what each field is doing ๐Ÿ‘‘

  • keyInfo contains the object identifier of the key-encryption algorithm (used to wrap the CEK) and NULL parameters.
  • entityUInfo optionally contains additional keying material supplied by the sending agent. when it's used with ECDH and CMS, the entityUInfo field contains the octet string ukm. when it's used with ECMQV and CMS, the entityUInfo contains the octet string addedukm (encoded in MQVuserKeyingMaterial).
  • suppPubInfo contains the length of the generated KEK, in bits, represented as a 32 bit number, as in [CMS-DH]. (e.g. for 3DES it would be 00 00 00 c0.) ๐Ÿ“

within CMS, ECC-CMS-SharedInfo is DER-encoded and used as input to the key derivation function, as specified in [SEC1, Section 3.6.1] ๐Ÿงš and ngl this is the part I'd flag to my bestie. ECC-CMS-SharedInfo is NOT the same as the OtherInfo from [CMS-DH]! here a counter value is not included in the keyInfo field, because the key derivation function specified in [SEC1, Section 3.6.1] already makes sure there's enough keying data. no counter needed, periodt ๐Ÿ™ˆ


9. Summary โœจ

okay the big picture: this document specifies how to use ECC algorithms with the S/MIME CMS. using an ECC algorithm within CMS can result in reduced processing requirements for S/MIME agents, and reduced bandwidth for CMS messages ๐ŸŒˆ lowkey iconic, honestly ๐Ÿ’œ


References

here's the whole reference list, every single entry ๐Ÿ“š

  • [X9.62] ANSI X9.62-1998, "Public Key Cryptography For The Financial Services Industry: The Elliptic Curve Digital Signature Algorithm (ECDSA)", American National Standards Institute, 1999.
  • [PKI-ALG] Bassham, L., Housley R. and W. Polk, "Algorithms and Identifiers for the Internet X.509 Public Key Infrastructure Certificate and CRL Profile", RFC 3279, April 2002.
  • [BON] D. Boneh, "The Security of Multicast MAC", Presentation at Selected Areas of Cryptography 2000, Center for Applied Cryptographic Research, University of Waterloo, 2000. Paper version available from http://crypto.stanford.edu/~dabo/papers/mmac.ps
  • [MUST] Bradner, S., "Key Words for Use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
  • [FIPS-180] FIPS 180-1, "Secure Hash Standard", National Institute of Standards and Technology, April 17, 1995.
  • [FIPS-186-2] FIPS 186-2, "Digital Signature Standard", National Institute of Standards and Technology, 15 February 2000.
  • [PKI] Housley, R., Polk, W., Ford, W. and D. Solo, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 3280, April 2002.
  • [CMS] Housley, R., "Cryptographic Message Syntax", RFC 2630, June 1999.
  • [IEEE1363] IEEE P1363, "Standard Specifications for Public Key Cryptography", Institute of Electrical and Electronics Engineers, 2000.
  • [K] B. Kaliski, "MQV Vulnerabilty", Posting to ANSI X9F1 and IEEE P1363 newsgroups, 1998.
  • [LMQSV] L. Law, A. Menezes, M. Qu, J. Solinas and S. Vanstone, "An efficient protocol for authenticated key agreement", Technical report CORR 98-05, University of Waterloo, 1998.
  • [CMS-KEA] Pawling, J., "CMS KEA and SKIPJACK Conventions", RFC 2876, July 2000.
  • [MSG] Ramsdell, B., "S/MIME Version 3 Message Specification", RFC 2633, June 1999.
  • [CMS-DH] Rescorla, E., "Diffie-Hellman Key Agreement Method", RFC 2631, June 1999.
  • [SEC1] SECG, "Elliptic Curve Cryptography", Standards for Efficient Cryptography Group, 2000. Available from www.secg.org/collateral/sec1.pdf.
  • [SEC2] SECG, "Recommended Elliptic Curve Domain Parameters", Standards for Efficient Cryptography Group, 2000. Available from www.secg.org/collateral/sec2.pdf.

Security Considerations ๐Ÿ”ฅ

okay this is the serious part, so listen up bestie ๐Ÿ™ˆ this specification is based on [CMS], [X9.62] and [SEC1], and the appropriate security considerations of those documents apply.

in addition, implementors of AuthenticatedData should be aware of the concerns expressed in [BON] when using AuthenticatedData to send messages to more than one recipient. also, users of MQV should be aware of the vulnerability in [K] ๐Ÿ’€

when 256, 384, and 512 bit hash functions succeed SHA-1 in future revisions of [FIPS], [FIPS-186-2], [X9.62] and [SEC1], then they can similarly succeed SHA-1 in a future revision of this document. so the upgrade path is basically already written in the sky โœจ

Intellectual Property Rights

the IETF has been notified of intellectual property rights claimed in regard to the specification contained in this document. for more information, consult the online list of claimed rights (http://www.ietf.org/ipr.html).

the IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document, or the extent to which any license under such rights might or might not be available. neither does it represent that it has made any effort to identify any such rights. information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP 11. copies of claims of rights made available for publication, and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification, can be obtained from the IETF Secretariat ๐ŸŒธ


Acknowledgments ๐Ÿซถ

the methods described in this document are based on work done by the ANSI X9F1 working group. the authors wish to extend their thanks to ANSI X9F1 for their assistance. the authors also wish to thank Peter de Rooij for his patient assistance. the technical comments of Francois Rousseau were valuable contributions ๐Ÿ’œ


Authors' Addresses

   Simon Blake-Wilson
   Certicom Corp
   5520 Explorer Drive #400
   Mississauga, ON L4W 5L1

   EMail: sblakewi@certicom.com


   Daniel R. L. Brown
   pCerticom Corp
   5520 Explorer Drive #400
   Mississauga, ON L4W 5L1

   EMail: dbrown@certicom.com


   Paul Lambert

   EMail: plambert@sprintmail.com

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