draft-ietf-smime-ecc-06.txt   rfc3278.txt 
INTERNET-DRAFT Simon Blake-Wilson, Certicom Corp
draft-ietf-smime-ecc-06.txt Daniel R. L. Brown, Certicom Corp
Paul Lambert, Cosine Communications
7 May, 2001 Expires: 6 November, 2001
Use of ECC Algorithms in CMS Network Working Group S. Blake-Wilson
Request for Comments: 3278 D. Brown
Category: Informational Certicom Corp
P. Lambert
Cosine Communications
April 2002
Status of this Memo Use of Elliptic Curve Cryptography (ECC) Algorithms
in Cryptographic Message Syntax (CMS)
This document is an Internet-Draft and is in full conformance with Status of this Memo
all provisions of Section 10 of RFC2026. Internet-Drafts are
working documents of the Internet Engineering Task Force (IETF),
its areas, and its working groups. Note that other groups may also
distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six This memo provides information for the Internet community. It does
months and may be updated, replaced, or obsoleted by other not specify an Internet standard of any kind. Distribution of this
documents at any time. It is inappropriate to use Internet-Drafts memo is unlimited.
as reference material or to cite them other than as "work in
progress."
The list of current Internet-Drafts can be accessed at Copyright Notice
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at Copyright (C) The Internet Society (2002). All Rights Reserved.
http://www.ietf.org/shadow.html.
Abstract Abstract
This document describes how to use Elliptic Curve Cryptography This document describes how to use Elliptic Curve Cryptography (ECC)
(ECC) public-key algorithms in the Cryptographic Message Syntax public-key algorithms in the Cryptographic Message Syntax (CMS). The
(CMS). The ECC algorithms support the creation of digital ECC algorithms support the creation of digital signatures and the
signatures and the exchange of keys to encrypt or authenticate exchange of keys to encrypt or authenticate content. The definition
content. The definition of the algorithm processing is based on of the algorithm processing is based on the ANSI X9.62 standard,
the ANSI X9.62 standard, developed by the ANSI X9F1 working group, developed by the ANSI X9F1 working group, the IEEE 1363 standard, and
and the IEEE 1363 standard and the SEC 1 standard. the SEC 1 standard.
The readers attention is called to the Intellectual Property Rights The readers attention is called to the Intellectual Property Rights
section at the end of this document. section at the end of this document.
Table of Contents Table of Contents
1 Introduction ........................................ 3 1 Introduction ................................................... 2
1.1 Requirements terminology ....................... 3 1.1 Requirements terminology .................................. 3
2 SignedData using ECC ................................ 3 2 SignedData using ECC .......................................... 3
2.1 SignedData using ECDSA ......................... 3 2.1 SignedData using ECDSA ................................... 3
2.1.1 Fields of the SignedData ................ 3 2.1.1 Fields of the SignedData .......................... 3
2.1.2 Actions of the sending agent ............ 4 2.1.2 Actions of the sending agent ...................... 4
2.1.3 Actions of the receiving agent .......... 4 2.1.3 Actions of the receiving agent .................... 4
3 EnvelopedData using ECC ............................. 5 3 EnvelopedData using ECC ....................................... 4
3.1 EnvelopedData using ECDH ....................... 5 3.1 EnvelopedData using ECDH ................................. 5
3.1.1 Fields of KeyAgreeRecipientInfo ......... 5 3.1.1 Fields of KeyAgreeRecipientInfo ................... 5
3.1.2 Actions of the sending agent ............ 6 3.1.2 Actions of the sending agent ...................... 5
3.1.3 Actions of the receiving agent .......... 6 3.1.3 Actions of the receiving agent .................... 6
3.2 EnvelopedData using 1-Pass ECMQV ............... 6 3.2 EnvelopedData using 1-Pass ECMQV ......................... 6
3.2.1 Fields of KeyAgreeRecipientInfo ......... 7 3.2.1 Fields of KeyAgreeRecipientInfo ................... 6
3.2.2 Actions of the sending agent ............ 7 3.2.2 Actions of the sending agent ...................... 7
3.2.3 Actions of the receiving agent .......... 8 3.2.3 Actions of the receiving agent .................... 7
4 AuthenticatedData using ECC ............ ............ 8 4 AuthenticatedData using ECC ............ ...................... 8
4.1 AuthenticatedData using 1-pass ECMQV ........... 8 4.1 AuthenticatedData using 1-pass ECMQV ..................... 8
4.1.1 Fields of KeyAgreeRecipientInfo ......... 8 4.1.1 Fields of KeyAgreeRecipientInfo ................... 8
4.1.2 Actions of the sending agent ............ 8 4.1.2 Actions of the sending agent ...................... 8
4.1.3 Actions of the receiving agent .......... 9 4.1.3 Actions of the receiving agent .................... 8
5 Recommended Algorithms and Elliptic Curves .......... 9 5 Recommended Algorithms and Elliptic Curves .................... 9
6 Certificates using ECC .............................. 9 6 Certificates using ECC ........................................ 9
7 SMIMECapabilities Attribute and ECC ................. 9 7 SMIMECapabilities Attribute and ECC ........................... 9
8 ASN.1 Syntax ........................................ 10 8 ASN.1 Syntax .................................................. 10
8.1 Algorithm identifiers .......................... 10 8.1 Algorithm identifiers .................................... 10
8.2 Other syntax ................................... 11 8.2 Other syntax ............................................. 11
9 Summary ............................................. 13 9 Summary ....................................................... 12
References ............................................. 13 References ....................................................... 13
Security Considerations ................................ 14 Security Considerations .......................................... 14
Intellectual Property Rights ........................... 14 Intellectual Property Rights ..................................... 14
Acknowledgments ........................................ 15 Acknowledgments .................................................. 15
Authors' Addresses ..................................... 15 Authors' Addresses ............................................... 15
Full Copyright Statement ............................... 16 Full Copyright Statement ......................................... 16
1 Introduction 1 Introduction
The Cryptographic Message Syntax (CMS) is cryptographic algorithm The Cryptographic Message Syntax (CMS) is cryptographic algorithm
independent. This specification defines a standard profile for the independent. This specification defines a profile for the use of
use of Elliptic Curve Cryptography (ECC) public key algorithms in Elliptic Curve Cryptography (ECC) public key algorithms in the CMS.
the CMS. The ECC algorithms are incorporated into the following The ECC algorithms are incorporated into the following CMS content
CMS content types: types:
- 'SignedData' to support ECC-based digital signature methods - 'SignedData' to support ECC-based digital signature methods
(ECDSA) to sign content (ECDSA) to sign content
- 'EnvelopedData' to support ECC-based public-key agreement - 'EnvelopedData' to support ECC-based public-key agreement
methods (ECDH and ECMQV) to generate pairwise key-encryption methods (ECDH and ECMQV) to generate pairwise key-encryption
keys to encrypt content-encryption keys used for content keys to encrypt content-encryption keys used for content
encryption encryption
- 'AuthenticatedData' to support ECC-based public-key agreement - 'AuthenticatedData' to support ECC-based public-key agreement
methods (ECMQV) to generate pairwise key-encryption keys to methods (ECMQV) to generate pairwise key-encryption keys to
encrypt MAC keys used for content authentication and integrity encrypt MAC keys used for content authentication and integrity
Certification of EC public keys is also described to provide Certification of EC public keys is also described to provide public-
public-key distribution in support of the specified techniques. key distribution in support of the specified techniques.
1.1 Requirements terminology 1.1 Requirements terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
this document are to be interpreted as described in RFC 2119 document are to be interpreted as described in BCP 14, RFC 2119
[MUST]. [MUST].
2 SignedData using ECC 2 SignedData using ECC
This section describes how to use ECC algorithms with the CMS This section describes how to use ECC algorithms with the CMS
SignedData format to sign data. SignedData format to sign data.
2.1 SignedData using ECDSA 2.1 SignedData using ECDSA
This section describes how to use the Elliptic Curve Digital This section describes how to use the Elliptic Curve Digital
Signature Algorithm (ECDSA) with SignedData. ECDSA is specified in Signature Algorithm (ECDSA) with SignedData. ECDSA is specified in
[X9.62]. The method is the elliptic curve analog of the [X9.62]. The method is the elliptic curve analog of the Digital
Digital Signature Algorithm (DSA) [FIPS 186-2]. Signature Algorithm (DSA) [FIPS 186-2].
In an implementation that uses ECDSA with CMS SignedData, the In an implementation that uses ECDSA with CMS SignedData, the
following techniques and formats MUST be used. following techniques and formats MUST be used.
2.1.1 Fields of the SignedData 2.1.1 Fields of the SignedData
When using ECDSA with SignedData the fields of SignerInfo are as in When using ECDSA with SignedData, the fields of SignerInfo are as in
[CMS], but with the following restrictions: [CMS], but with the following restrictions:
digestAlgorithm MUST contain the algorithm identifier sha-1 (see digestAlgorithm MUST contain the algorithm identifier sha-1 (see
Section 8.1) which identifies the SHA-1 hash algorithm. Section 8.1) which identifies the SHA-1 hash algorithm.
signatureAlgorithm contains the algorithm identifier signatureAlgorithm contains the algorithm identifier ecdsa-with-
ecdsa-with-SHA1 (see Section 8.1) which identifies the ECDSA SHA1 (see Section 8.1) which identifies the ECDSA signature
signature algorithm. algorithm.
signature MUST contain the DER encoding (as an octet string) of signature MUST contain the DER encoding (as an octet string) of a
a value of the ASN.1 type ECDSA-Sig-Value (see Section 8.2). value of the ASN.1 type ECDSA-Sig-Value (see Section 8.2).
When using ECDSA, the SignedData certificates field MAY include the When using ECDSA, the SignedData certificates field MAY include the
certificate(s) for the EC public key(s) used in the generation of certificate(s) for the EC public key(s) used in the generation of the
the ECDSA signatures in SignedData. ECC certificates are discussed ECDSA signatures in SignedData. ECC certificates are discussed in
in Section 6. Section 6.
2.1.2 Actions of the sending agent 2.1.2 Actions of the sending agent
When using ECDSA with SignedData, the sending agent uses the When using ECDSA with SignedData, the sending agent uses the message
message digest calculation process and signature generation process digest calculation process and signature generation process for
for SignedData that are specified in [CMS]. To sign data, the SignedData that are specified in [CMS]. To sign data, the sending
sending agent uses the signature method specified in [X9.62, agent uses the signature method specified in [X9.62, Section 5.3]
Section 5.3] with the following exceptions: with the following exceptions:
- In [X9.62, Section 5.3.1], the integer "e" is instead - In [X9.62, Section 5.3.1], the integer "e" is instead
determined by converting the message digest generated determined by converting the message digest generated according
according to [CMS, Section 5.4] to an integer using the data to [CMS, Section 5.4] to an integer using the data conversion
conversion method in [X9.62, Section 4.3.2]. method in [X9.62, Section 4.3.2].
The sending agent encodes the resulting signature using the The sending agent encodes the resulting signature using the ECDSA-
ECDSA-Sig-Value syntax (see Section 8.2) and places it in the Sig-Value syntax (see Section 8.2) and places it in the SignerInfo
SignerInfo signature field. signature field.
2.1.3 Actions of the receiving agent 2.1.3 Actions of the receiving agent
When using ECDSA with SignedData, the receiving agent uses the When using ECDSA with SignedData, the receiving agent uses the
message digest calculation process and signature verification message digest calculation process and signature verification process
process for SignedData that are specified in [CMS]. To verify for SignedData that are specified in [CMS]. To verify SignedData,
SignedData, the receiving agent uses the signature verification the receiving agent uses the signature verification method specified
method specified in [X9.62, Section 5.4] with the following in [X9.62, Section 5.4] with the following exceptions:
exceptions:
- In [X9.62, Section 5.4.1] the integer "e'" is instead - In [X9.62, Section 5.4.1] the integer "e'" is instead
determined by converting the message digest generated determined by converting the message digest generated according
according to [CMS, Section 5.4] to an integer using the data to [CMS, Section 5.4] to an integer using the data conversion
conversion method in [X9.62, Section 4.3.2]. method in [X9.62, Section 4.3.2].
In order to verify the signature, the receiving agent retrieves the In order to verify the signature, the receiving agent retrieves the
integers r and s from the SignerInfo signature field of the integers r and s from the SignerInfo signature field of the received
received message. message.
3 EnvelopedData using ECC Algorithms 3 EnvelopedData using ECC Algorithms
This section describes how to use ECC algorithms with the CMS This section describes how to use ECC algorithms with the CMS
EnvelopedData format. EnvelopedData format.
3.1 EnvelopedData using (ephemeral-static) ECDH 3.1 EnvelopedData using (ephemeral-static) ECDH
This section describes how to use ephemeral-static Elliptic Curve This section describes how to use the ephemeral-static Elliptic Curve
Diffie-Hellman (ECDH) key agreement algorithm with EnvelopedData. Diffie-Hellman (ECDH) key agreement algorithm with EnvelopedData.
Ephemeral-static ECDH is specified in [SEC1] and [IEEE1363]. Ephemeral-static ECDH is specified in [SEC1] and [IEEE1363].
Ephemeral-static ECDH is the the elliptic curve analog of the Ephemeral-static ECDH is the the elliptic curve analog of the
ephemeral-static Diffie-Hellman key agreement algorithm specified ephemeral-static Diffie-Hellman key agreement algorithm specified
jointly in the documents [CMS, Section 12.3.1.1] and [CMS-DH]. jointly in the documents [CMS, Section 12.3.1.1] and [CMS-DH].
In an implementation that uses ECDH with CMS EnvelopedData with key In an implementation that uses ECDH with CMS EnvelopedData with key
agreement, the following techniques and formats MUST be used. agreement, the following techniques and formats MUST be used.
3.1.1 Fields of KeyAgreeRecipientInfo 3.1.1 Fields of KeyAgreeRecipientInfo
skipping to change at page 5, line 35 skipping to change at page 5, line 30
KeyAgreeRecipientInfo are as in [CMS], but with the following KeyAgreeRecipientInfo are as in [CMS], but with the following
restrictions: restrictions:
originator MUST be the alternative originatorKey. The originator MUST be the alternative originatorKey. The
originatorKey algorithm field MUST contain the id-ecPublicKey originatorKey algorithm field MUST contain the id-ecPublicKey
object identifier (see Section 8.1) with NULL parameters. The object identifier (see Section 8.1) with NULL parameters. The
originatorKey publicKey field MUST contain the DER-encoding of a originatorKey publicKey field MUST contain the DER-encoding of a
value of the ASN.1 type ECPoint (see Section 8.2), which value of the ASN.1 type ECPoint (see Section 8.2), which
represents the sending agent's ephemeral EC public key. represents the sending agent's ephemeral EC public key.
keyEncryptionAlgorithm MUST contain the keyEncryptionAlgorithm MUST contain the dhSinglePass-stdDH-
dhSinglePass-stdDH-sha1kdf-scheme object identifier (see Section sha1kdf-scheme object identifier (see Section 8.1) if standard
8.1) if standard ECDH primitive is used, or the ECDH primitive is used, or the dhSinglePass-cofactorDH-sha1kdf-
dhSinglePass-cofactorDH-sha1kdf-scheme object identifier (see scheme object identifier (see Section 8.1) if the cofactor ECDH
Section 8.1) if the cofactor ECDH primitive is used. The primitive is used. The parameters field contains
parameters field contains KeyWrapAlgorithm. The KeyWrapAlgorithm. The KeyWrapAlgorithm is the algorithm
KeyWrapAlgorithm is the algorithm identifier that indicates the identifier that indicates the symmetric encryption algorithm used
symmetric encryption algorithm used to encrypt the CEK with the to encrypt the content-encryption key (CEK) with the key-
KEK. encryption key (KEK).
3.1.2 Actions of the sending agent 3.1.2 Actions of the sending agent
When using ephemeral-static ECDH with EnvelopedData, the sending When using ephemeral-static ECDH with EnvelopedData, the sending
agent first obtains the recipient's EC public key and domain agent first obtains the recipient's EC public key and domain
parameters (e.g. from the recipient's certificate). The sending parameters (e.g. from the recipient's certificate). The sending
agent then determines an integer "keydatalen", which is the agent then determines an integer "keydatalen", which is the
KeyWrapAlgorithm symmetric key-size in bits, and also a bit string KeyWrapAlgorithm symmetric key-size in bits, and also a bit string
"SharedInfo", which is the DER encoding of ECC-CMS-SharedInfo (see "SharedInfo", which is the DER encoding of ECC-CMS-SharedInfo (see
Section 8.2). The sending agent then performs the key deployment Section 8.2). The sending agent then performs the key deployment and
and the key agreement operation of the Elliptic Curve the key agreement operation of the Elliptic Curve Diffie-Hellman
Diffie-Hellman Scheme specified in [SEC1, Section 6.1]. As a Scheme specified in [SEC1, Section 6.1]. As a result the sending
result the sending agent obtains: agent obtains:
- an ephemeral public key, which is represented as a value of - an ephemeral public key, which is represented as a value of the
the type ECPoint (see Section 8.2), encapsulated in a bit type ECPoint (see Section 8.2), encapsulated in a bit string
string and placed in the KeyAgreeRecipientInfo originator and placed in the KeyAgreeRecipientInfo originator field, and
field, and
- a shared secret bit string "K" which is used as the pairwise - a shared secret bit string "K", which is used as the pairwise
key-encryption key for that recipient, as specified in [CMS]. key-encryption key for that recipient, as specified in [CMS].
3.1.3 Actions of the receiving agent 3.1.3 Actions of the receiving agent
When using ephemeral-static ECDH with EnvelopedData, the receiving When using ephemeral-static ECDH with EnvelopedData, the receiving
agent determines the bit string "SharedInfo", which is the DER agent determines the bit string "SharedInfo", which is the DER
encoding of ECC-CMS-SharedInfo (see Section 8.2), and the integer encoding of ECC-CMS-SharedInfo (see Section 8.2), and the integer
"keydatalen" from the key-size, in bits, of the KeyWrapAlgorithm. "keydatalen" from the key-size, in bits, of the KeyWrapAlgorithm.
The receiving agent retrieves the ephemeral EC public key from the The receiving agent retrieves the ephemeral EC public key from the
bit string KeyAgreeRecipientInfo originator, which an value of the bit string KeyAgreeRecipientInfo originator, with a value of the type
type ECPoint (see Section 8.2) encapsulated as a bit string. The ECPoint (see Section 8.2) encapsulated as a bit string. The
receiving agent performs the key agreement operation of the receiving agent performs the key agreement operation of the Elliptic
Elliptic Curve Diffie-Hellman Scheme specified in [SEC1, Section Curve Diffie-Hellman Scheme specified in [SEC1, Section 6.1]. As a
6.1]. As a result the receiving agent obtains a shared secret bit result, the receiving agent obtains a shared secret bit string "K",
string "K" which is used as the pairwise key-encryption key to which is used as the pairwise key-encryption key to unwrap the CEK.
unwrap the CEK.
3.2 EnvelopedData using 1-Pass ECMQV 3.2 EnvelopedData using 1-Pass ECMQV
This section describes how to use the 1-Pass elliptic curve MQV This section describes how to use the 1-Pass elliptic curve MQV
(ECMQV) key agreement algorithm with EnvelopedData. ECMQV is (ECMQV) key agreement algorithm with EnvelopedData. ECMQV is
specified in [SEC1] and [IEEE1363]. Like the KEA algorithm specified in [SEC1] and [IEEE1363]. Like the KEA algorithm [CMS-
[CMS-KEA], 1-Pass ECMQV uses three key pairs: an ephemeral key KEA], 1-Pass ECMQV uses three key pairs: an ephemeral key pair, a
pair, a static key pair of the sending agent, and a static key pair static key pair of the sending agent, and a static key pair of the
of the receiving agent. An advantage of using 1-Pass ECMQV is that receiving agent. An advantage of using 1-Pass ECMQV is that it can
it can be used with both EnvelopedData and AuthenticatedData. be used with both EnvelopedData and AuthenticatedData.
In an implementation that uses 1-Pass ECMQV with CMS EnvelopedData In an implementation that uses 1-Pass ECMQV with CMS EnvelopedData
with key agreement, the following techniques and formats MUST be with key agreement, the following techniques and formats MUST be
used. used.
3.2.1 Fields of KeyAgreeRecipientInfo 3.2.1 Fields of KeyAgreeRecipientInfo
When using 1-Pass ECMQV with EnvelopedData the fields of When using 1-Pass ECMQV with EnvelopedData, the fields of
KeyAgreeRecipientInfo are: KeyAgreeRecipientInfo are:
originator identifies the static EC public key of the sender. originator identifies the static EC public key of the sender. It
It SHOULD be the one of the alternatives issuerAndSerialNumber SHOULD be one of the alternatives, issuerAndSerialNumber or
or subjectKeyIdentifier and point to one of the sending agent's subjectKeyIdentifier, and point to one of the sending agent's
certificates. certificates.
ukm MUST be present. The ukm field MUST contain an octet string ukm MUST be present. The ukm field MUST contain an octet string
which is the DER encoding of the type MQVuserKeyingMaterial (see which is the DER encoding of the type MQVuserKeyingMaterial (see
Section 8.2). The MQVuserKeyingMaterial ephemeralPublicKey Section 8.2). The MQVuserKeyingMaterial ephemeralPublicKey
algorithm field MUST contain the id-ecPublicKey object algorithm field MUST contain the id-ecPublicKey object identifier
identifier (see Section 8.1) with NULL parameters field. The (see Section 8.1) with NULL parameters field. The
MQVuserKeyingMaterial ephemeralPublicKey publicKey field MUST MQVuserKeyingMaterial ephemeralPublicKey publicKey field MUST
contain the DER-encoding of the ASN.1 type ECPoint (see Section contain the DER-encoding of the ASN.1 type ECPoint (see Section
8.2) representing sending agent's ephemeral EC public key. The 8.2) representing sending agent's ephemeral EC public key. The
MQVuserKeyingMaterial addedukm field, if present, SHOULD contain MQVuserKeyingMaterial addedukm field, if present, SHOULD contain
an octet string of additional user keying material of the an octet string of additional user keying material of the sending
sending agent. agent.
keyEncryptionAlgorithm MUST be the mqvSinglePass-sha1kdf-scheme keyEncryptionAlgorithm MUST be the mqvSinglePass-sha1kdf-scheme
algorithm identifier (see Section 8.1), with parameters field algorithm identifier (see Section 8.1), with the parameters field
KeyWrapAlgorithm. The KeyWrapAlgorithm indicates the symmetric KeyWrapAlgorithm. The KeyWrapAlgorithm indicates the symmetric
encryption algorithm used to encrypt the CEK with the KEK encryption algorithm used to encrypt the CEK with the KEK
generated using the 1-Pass ECMQV algorithm. generated using the 1-Pass ECMQV algorithm.
3.2.2 Actions of the sending agent 3.2.2 Actions of the sending agent
When using 1-Pass ECMQV with EnvelopedData, the sending agent first When using 1-Pass ECMQV with EnvelopedData, the sending agent first
obtains the recipient's EC public key and domain parameters, obtains the recipient's EC public key and domain parameters, (e.g.
(e.g. from the recipient's certificate) and checks that the domain from the recipient's certificate) and checks that the domain
parameters are the same. The sending agent then determines an parameters are the same. The sending agent then determines an
integer "keydatalen", which is the KeyWrapAlgorithm symmetric integer "keydatalen", which is the KeyWrapAlgorithm symmetric key-
key-size in bits, and also a bit string "SharedInfo", which is the size in bits, and also a bit string "SharedInfo", which is the DER
DER encoding of ECC-CMS-SharedInfo (see Section 8.2). The sending encoding of ECC-CMS-SharedInfo (see Section 8.2). The sending agent
agent then performs the key deployment and key agreement operations then performs the key deployment and key agreement operations of the
of the Elliptic Curve MQV Scheme specified in [SEC1, Section 6.2]. Elliptic Curve MQV Scheme specified in [SEC1, Section 6.2]. As a
As a result the sending agent obtains result, the sending agent obtains:
- an ephemeral public key, which is represented as a value of - an ephemeral public key, which is represented as a value of
type ECPoint (see Section 8.2), encapsulated in a bit string, type ECPoint (see Section 8.2), encapsulated in a bit string,
placed in an MQVuserKeyingMaterial ephemeralPublicKey placed in an MQVuserKeyingMaterial ephemeralPublicKey publicKey
publicKey field (see Section 8.2), and field (see Section 8.2), and
- a shared secret bit string "K" which is used as the pairwise - a shared secret bit string "K", which is used as the pairwise
key-encryption key for that recipient, as specified in [CMS]. key-encryption key for that recipient, as specified in [CMS].
The ephemeral public key can be re-used with an AuthenticatedData The ephemeral public key can be re-used with an AuthenticatedData for
for greater efficiency. greater efficiency.
3.2.3 Actions of the receiving agent 3.2.3 Actions of the receiving agent
When using 1-Pass ECMQV with EnvelopedData, the receiving agent When using 1-Pass ECMQV with EnvelopedData, the receiving agent
determines the bit string "SharedInfo", which is the DER encoding determines the bit string "SharedInfo", which is the DER encoding of
of ECC-CMS-SharedInfo (see Section 8.2), and the integer ECC-CMS-SharedInfo (see Section 8.2), and the integer "keydatalen"
"keydatalen" from the key-size, in bits, of the KeyWrapAlgorithm. from the key-size, in bits, of the KeyWrapAlgorithm. The receiving
The receiving agent then retrieves the static and ephemeral EC agent then retrieves the static and ephemeral EC public keys of the
public keys of the originator, from the originator and ukm fields originator, from the originator and ukm fields as described in
as described in Section 3.2.1, and its static EC public key Section 3.2.1, and its static EC public key identified in the rid
identified in the rid field and checks that the domain parameters field and checks that the domain parameters are the same. The
are the same. The receiving agent then performs the key agreement receiving agent then performs the key agreement operation of the
operation of the Elliptic Curve MQV Scheme [SEC1, Section 6.2]. As Elliptic Curve MQV Scheme [SEC1, Section 6.2]. As a result, the
a result the receiving agent obtains a shared secret bit string "K" receiving agent obtains a shared secret bit string "K" which is used
which is used as the pairwise key-encryption key to unwrap the CEK. as the pairwise key-encryption key to unwrap the CEK.
4 AuthenticatedData using ECC 4 AuthenticatedData using ECC
This section describes how to use ECC algorithms with the CMS This section describes how to use ECC algorithms with the CMS
AuthenticatedData format. AuthenticatedData lacks non-repudiation, AuthenticatedData format. AuthenticatedData lacks non-repudiation,
and so in some instances is preferable to SignedData. (For and so in some instances is preferable to SignedData. (For example,
example, the sending agent might not want the message to be the sending agent might not want the message to be authenticated when
authenticated when forwarded.) forwarded.)
4.1 AuthenticatedData using 1-pass ECMQV 4.1 AuthenticatedData using 1-pass ECMQV
This section describes how to use the 1-Pass elliptic curve MQV This section describes how to use the 1-Pass elliptic curve MQV
(ECMQV) key agreement algorithm with AuthenticatedData. ECMQV is (ECMQV) key agreement algorithm with AuthenticatedData. ECMQV is
specified in [SEC1]. An advantage of using 1-Pass ECMQV is that it specified in [SEC1]. An advantage of using 1-Pass ECMQV is that it
can be used with both EnvelopedData and AuthenticatedData. can be used with both EnvelopedData and AuthenticatedData.
4.1.1 Fields of the KeyAgreeRecipientInfo 4.1.1 Fields of the KeyAgreeRecipientInfo
The AuthenticatedData KeyAgreeRecipientInfo fields are used in the The AuthenticatedData KeyAgreeRecipientInfo fields are used in the
same manner as the fields for the corresponding EnvelopedData same manner as the fields for the corresponding EnvelopedData
KeyAgreeRecipientInfo fields of Section 3.2.1 of this document. KeyAgreeRecipientInfo fields of Section 3.2.1 of this document.
4.1.2 Actions of the sending agent 4.1.2 Actions of the sending agent
The sending agent uses the same actions as for EnvelopedData The sending agent uses the same actions as for EnvelopedData with 1-
with 1-Pass ECMQV, as specified in Section 3.2.2 of this document. Pass ECMQV, as specified in Section 3.2.2 of this document.
The ephemeral public key can be re-used with an EnvelopedData for The ephemeral public key can be re-used with an EnvelopedData for
greater efficiency. greater efficiency.
Note: if there are multiple recipients then an attack is possible Note: if there are multiple recipients, an attack is possible where
where one recipient modifies the content without other recipients one recipient modifies the content without other recipients noticing
noticing [BON]. A sending agent who is concerned with such an [BON]. A sending agent who is concerned with such an attack SHOULD
attack SHOULD use a separate AuthenticatedData for each recipient. use a separate AuthenticatedData for each recipient.
4.1.3 Actions of the receiving agent 4.1.3 Actions of the receiving agent
The receiving agent uses the same actions as for EnvelopedData The receiving agent uses the same actions as for EnvelopedData with
with 1-Pass ECMQV, as specified in Section 3.2.3 of this document. 1-Pass ECMQV, as specified in Section 3.2.3 of this document.
Note: see Note in Section 4.1.2. Note: see Note in Section 4.1.2.
5 Recommended Algorithms and Elliptic Curves 5 Recommended Algorithms and Elliptic Curves
Implementations of this specification MUST implement either Implementations of this specification MUST implement either
SignedData with ECDSA or EnvelopedData with ephemeral-static ECDH. SignedData with ECDSA or EnvelopedData with ephemeral-static ECDH.
Implementations of this specification SHOULD implement both Implementations of this specification SHOULD implement both
SignedData with ECDSA and EnvelopedData with ephemeral-static ECDH. SignedData with ECDSA and EnvelopedData with ephemeral-static ECDH.
Implementations MAY implement the other techniques specified, such Implementations MAY implement the other techniques specified, such as
as AuthenticatedData and 1-Pass ECMQV. AuthenticatedData and 1-Pass ECMQV.
Furthermore, in order to encourage interoperability, Furthermore, in order to encourage interoperability, implementations
implementations SHOULD use the elliptic curve domain parameters SHOULD use the elliptic curve domain parameters specified by ANSI
specified by ANSI [X9.62], NIST [FIPS-186-2] and SECG [SEC2]. [X9.62], NIST [FIPS-186-2] and SECG [SEC2].
6 Certificates using ECC 6 Certificates using ECC
Internet X.509 certificates [PKI] can be used in conjunction with Internet X.509 certificates [PKI] can be used in conjunction with
this specification to distribute agents' public keys. The use of this specification to distribute agents' public keys. The use of ECC
ECC algorithms and keys within X.509 certificates is specified in algorithms and keys within X.509 certificates is specified in [PKI-
[PKI-ALG]. ALG].
7 SMIMECapabilities Attribute and ECC 7 SMIMECapabilities Attribute and ECC
A sending agent MAY announce to receiving agents that it supports A sending agent MAY announce to receiving agents that it supports one
one or more of the ECC algorithms in this document by using the or more of the ECC algorithms in this document by using the
SMIMECapabilities signed attribute [MSG, Section 2.5.2]. SMIMECapabilities signed attribute [MSG, Section 2.5.2].
The SMIMECapability value to indicate support for the ECDSA The SMIMECapability value to indicate support for the ECDSA signature
signature algorithm is the SEQUENCE with the capabilityID field algorithm is the SEQUENCE with the capabilityID field containing the
containing the object identifier ecdsa-with-SHA1 with NULL object identifier ecdsa-with-SHA1 with NULL parameters. The DER
parameters. The DER encoding is: encoding is:
30 0b 06 07 2a 86 48 ce 3d 04 01 05 00 30 0b 06 07 2a 86 48 ce 3d 04 01 05 00
The SMIMECapability capabilityID object identifiers for the The SMIMECapability capabilityID object identifiers for the supported
supported key agreement algorithms in this document are key agreement algorithms in this document are dhSinglePass-stdDH-
dhSinglePass-stdDH-sha1kdf-scheme, sha1kdf-scheme, dhSinglePass-cofactorDH-sha1kdf-scheme, and
dhSinglePass-cofactorDH-sha1kdf-scheme, and
mqvSinglePass-sha1kdf-scheme. For each of these SMIMECapability mqvSinglePass-sha1kdf-scheme. For each of these SMIMECapability
SEQUENCEs the parameters field is present and indicates the SEQUENCEs, the parameters field is present and indicates the
supported key-encryption algorithm with the KeyWrapAlgorithm supported key-encryption algorithm with the KeyWrapAlgorithm
algorithm identifier. The DER encodings that indicate capability algorithm identifier. The DER encodings that indicate capability of
of the three key agreement algorithms with CMS Triple-DES key wrap the three key agreement algorithms with CMS Triple-DES key wrap are:
are:
30 1c 06 09 2b 81 05 10 86 48 3f 00 02 30 0f 06 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 0b 2a 86 48 86 f7 0d 01 09 10 03 06 05 00
for ephemeral-static ECDH, for ephemeral-static ECDH,
30 1c 06 09 2b 81 05 10 86 48 3f 00 03 30 0f 06 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 0b 2a 86 48 86 f7 0d 01 09 10 03 06 05 00
for ephemeral-static ECDH with cofactor method, and for ephemeral-static ECDH with cofactor method, and
30 1c 06 09 2b 81 05 10 86 48 3f 00 10 30 0f 06 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 0b 2a 86 48 86 f7 0d 01 09 10 03 06 05 00
for ECMQV. for ECMQV.
skipping to change at page 10, line 33 skipping to change at page 10, line 16
for ephemeral-static ECDH with cofactor method, and for ephemeral-static ECDH with cofactor method, and
30 1c 06 09 2b 81 05 10 86 48 3f 00 10 30 0f 06 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 0b 2a 86 48 86 f7 0d 01 09 10 03 06 05 00
for ECMQV. for ECMQV.
8 ASN.1 Syntax 8 ASN.1 Syntax
The ASN.1 syntax that is used in this document is gathered together The ASN.1 syntax used in this document is gathered in this section
in this section for reference purposes. for reference purposes.
8.1 Algorithm identifiers 8.1 Algorithm identifiers
The algorithm identifiers used in this document are taken from The algorithm identifiers used in this document are taken from
[X9.62], [SEC1] and [SEC2]. [X9.62], [SEC1] and [SEC2].
The following object identifier indicates the hash algorithm used The following object identifier indicates the hash algorithm used in
in this document: this document:
sha-1 OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) sha-1 OBJECT IDENTIFIER ::= { iso(1) identified-organization(3)
oiw(14) secsig(3) algorithm(2) 26 } oiw(14) secsig(3) algorithm(2) 26 }
The following object identifier is used in this document to The following object identifier is used in this document to indicate
indicate an elliptic curve public key: an elliptic curve public key:
id-ecPublicKey OBJECT IDENTIFIER ::= { ansi-x9-62 keyType(2) 1 } id-ecPublicKey OBJECT IDENTIFIER ::= { ansi-x9-62 keyType(2) 1 }
where where
ansi-x9-62 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) ansi-x9-62 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840)
10045 } 10045 }
When the object identifier id-ecPublicKey is used here with an When the object identifier id-ecPublicKey is used here with an
algorithm identifier, the associated parameters contain NULL. algorithm identifier, the associated parameters contain NULL.
The following object identifier indicates the digital signature The following object identifier indicates the digital signature
algorithm used in this document: algorithm used in this document:
ecdsa-with-SHA1 OBJECT IDENTIFIER ::= { ansi-x9-62 signatures(4) ecdsa-with-SHA1 OBJECT IDENTIFIER ::= { ansi-x9-62 signatures(4)
1 } 1 }
When the object identifier ecdsa-with-SHA1 is used within an When the object identifier ecdsa-with-SHA1 is used within an
algorithm identifier, the associated parameters field contains algorithm identifier, the associated parameters field contains NULL.
NULL.
The following object identifiers indicate the key agreement The following object identifiers indicate the key agreement
algorithms used in this document: algorithms used in this document:
dhSinglePass-stdDH-sha1kdf-scheme OBJECT IDENTIFIER ::= { dhSinglePass-stdDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 2} x9-63-scheme 2}
dhSinglePass-cofactorDH-sha1kdf-scheme OBJECT IDENTIFIER ::= { dhSinglePass-cofactorDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 3} x9-63-scheme 3}
skipping to change at page 11, line 49 skipping to change at page 11, line 34
x9-63(63) schemes(0) } x9-63(63) schemes(0) }
When the object identifiers are used here within an algorithm When the object identifiers are used here within an algorithm
identifier, the associated parameters field contains the CMS identifier, the associated parameters field contains the CMS
KeyWrapAlgorithm algorithm identifier. KeyWrapAlgorithm algorithm identifier.
8.2 Other syntax 8.2 Other syntax
The following additional syntax is used here. The following additional syntax is used here.
When using ECDSA with SignedData, ECDSA signatures are encoded When using ECDSA with SignedData, ECDSA signatures are encoded using
using the type: the type:
ECDSA-Sig-Value ::= SEQUENCE { ECDSA-Sig-Value ::= SEQUENCE {
r INTEGER, r INTEGER,
s INTEGER } s INTEGER }
ECDSA-Sig-Value is specified in [X9.62]. Within CMS, ECDSA-Sig-Value is specified in [X9.62]. Within CMS, ECDSA-Sig-Value
ECDSA-Sig-Value is DER-encoded and placed within a signature field is DER-encoded and placed within a signature field of SignedData.
of SignedData.
When using ECDH and ECMQV with EnvelopedData and AuthenticatedData, When using ECDH and ECMQV with EnvelopedData and AuthenticatedData,
ephemeral and static public keys are encoded using the type ephemeral and static public keys are encoded using the type ECPoint.
ECPoint.
ECPoint ::= OCTET STRING ECPoint ::= OCTET STRING
When using ECMQV with EnvelopedData and AuthenticatedData, the When using ECMQV with EnvelopedData and AuthenticatedData, the
sending agent's ephemeral public key and additional keying material sending agent's ephemeral public key and additional keying material
are encoded using the type: are encoded using the type:
MQVuserKeyingMaterial ::= SEQUENCE { MQVuserKeyingMaterial ::= SEQUENCE {
ephemeralPublicKey OriginatorPublicKey, ephemeralPublicKey OriginatorPublicKey,
addedukm [0] EXPLICIT UserKeyingMaterial OPTIONAL } addedukm [0] EXPLICIT UserKeyingMaterial OPTIONAL }
The ECPoint syntax in used to represent the ephemeral public key The ECPoint syntax in used to represent the ephemeral public key and
and placed in the ephemeralPublicKey field. The additional user placed in the ephemeralPublicKey field. The additional user keying
keying material is place in the addedukm field. Then the material is placed in the addedukm field. Then the
MQVuserKeyingMaterial value is DER-encoded and placed within in a MQVuserKeyingMaterial value is DER-encoded and placed within a ukm
ukm field of EnvelopedData or AuthenticatedData. field of EnvelopedData or AuthenticatedData.
When using ECDH or ECMQV with EnvelopedData or AuthenticatedData, When using ECDH or ECMQV with EnvelopedData or AuthenticatedData, the
the key-encryption keys are derived by using the type: key-encryption keys are derived by using the type:
ECC-CMS-SharedInfo ::= SEQUENCE { ECC-CMS-SharedInfo ::= SEQUENCE {
keyInfo AlgorithmIdentifier, keyInfo AlgorithmIdentifier,
entityUInfo [0] EXPLICIT OCTET STRING OPTIONAL, entityUInfo [0] EXPLICIT OCTET STRING OPTIONAL,
suppPubInfo [2] EXPLICIT OCTET STRING } suppPubInfo [2] EXPLICIT OCTET STRING }
The fields of ECC-CMS-SharedInfo are as follows: The fields of ECC-CMS-SharedInfo are as follows:
keyInfo contains the object identifier of the key-encryption keyInfo contains the object identifier of the key-encryption
algorithm (used to wrap the CEK) and NULL parameters. algorithm (used to wrap the CEK) and NULL parameters.
entityUInfo optionally contains additional keying material entityUInfo optionally contains additional keying material
supplied by the sending agent. When used with ECDH and CMS, the supplied by the sending agent. When used with ECDH and CMS, the
entityUInfo field contains the octet string ukm. When used with entityUInfo field contains the octet string ukm. When used with
ECMQV and CMS, the entityUInfo contains the octet string ECMQV and CMS, the entityUInfo contains the octet string addedukm
addedukm (encoded in MQVuserKeyingMaterial). (encoded in MQVuserKeyingMaterial).
suppPubInfo contains the length of the generated KEK, in bits, suppPubInfo contains the length of the generated KEK, in bits,
represented as a 32 bit number, as in [CMS-DH]. (E.g. for 3DES represented as a 32 bit number, as in [CMS-DH]. (E.g. for 3DES it
it would be 00 00 00 c0.) would be 00 00 00 c0.)
Within CMS, ECC-CMS-SharedInfo is DER-encoded and used as input to 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]. the key derivation function, as specified in [SEC1, Section 3.6.1].
Note that ECC-CMS-SharedInfo differs from the OtherInfo specified Note that ECC-CMS-SharedInfo differs from the OtherInfo specified in
in [CMS-DH]. Here a counter value is not included in the keyInfo [CMS-DH]. Here, a counter value is not included in the keyInfo field
field because the key derivation function specified in [SEC1, because the key derivation function specified in [SEC1, Section
Section 3.6.1] ensures that sufficient keying data is provided. 3.6.1] ensures that sufficient keying data is provided.
9 Summary 9 Summary
This document specifies how to use ECC algorithms with the S/MIME This document specifies how to use ECC algorithms with the S/MIME
CMS. Use of ECC algorithm within CMS can result in reduced CMS. Use of ECC algorithm within CMS can result in reduced
processing requirements for S/MIME agents, and reduced bandwidth processing requirements for S/MIME agents, and reduced bandwidth for
for CMS messages. CMS messages.
References References
[X9.62] ANSI X9.62-1998, "Public Key Cryptography For The [X9.62] ANSI X9.62-1998, "Public Key Cryptography For The
Financial Services Industry: The Elliptic Curve Financial Services Industry: The Elliptic Curve Digital
Digital Signature Algorithm (ECDSA)", American Signature Algorithm (ECDSA)", American National
National Standards Institute, 1999. Standards Institute, 1999.
[PKI-ALG] L. Bassham, R. Housley and W. Polk, "Algorithms and [PKI-ALG] Bassham, L., Housley R. and W. Polk, "Algorithms and
Identifiers for the Internet X.509 Public Key Identifiers for the Internet X.509 Public Key
Infrastructure Certificate and CRL profile", PKIX Infrastructure Certificate and CRL Profile", RFC 3279,
Working Group Internet-Draft, November 2000. April 2002.
[BON] D. Boneh, "The Security of Multicast MAC", [BON] D. Boneh, "The Security of Multicast MAC", Presentation
Presentation at Selected Areas of Cryptography 2000, at Selected Areas of Cryptography 2000, Center for
Center for Applied Cryptographic Research, University Applied Cryptographic Research, University of Waterloo,
of Waterloo, 2000. Paper version available from 2000. Paper version available from
http://crypto.stanford.edu/~dabo/papers/mmac.ps http://crypto.stanford.edu/~dabo/papers/mmac.ps
[MUST] S. Bradner, "Key Words for Use in RFCs to Indicate [MUST] Bradner, S., "Key Words for Use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[FIPS-180] FIPS 180-1, "Secure Hash Standard", National Institute [FIPS-180] FIPS 180-1, "Secure Hash Standard", National Institute
of Standards and Technology, April 17, 1995. of Standards and Technology, April 17, 1995.
[FIPS-186-2] FIPS 186-2, "Digital Signature Standard", National [FIPS-186-2] FIPS 186-2, "Digital Signature Standard", National
Institute of Standards and Technology, 15 February Institute of Standards and Technology, 15 February 2000.
2000.
[PKI] W. Ford, R. Housley, W. Polk and D. Solo, "Internet X.509 [PKI] Housley, R., Polk, W., Ford, W. and D. Solo, "Internet
Public Key Infrastructure Certificate and CRL X.509 Public Key Infrastructure Certificate and
Profile", PKIX Working Group Internet-Draft, January Certificate Revocation List (CRL) Profile", RFC 3280,
2001. April 2002.
[CMS] R. Housley, "Cryptographic Message Syntax", RFC 2630, [CMS] Housley, R., "Cryptographic Message Syntax", RFC 2630,
June 1999. June 1999.
[IEEE1363] IEEE P1363, "Standard Specifications for Public Key [IEEE1363] IEEE P1363, "Standard Specifications for Public Key
Cryptography", Institute of Electrical and Electronics Cryptography", Institute of Electrical and Electronics
Engineers, 2000. Engineers, 2000.
[K] B. Kaliski, "MQV Vulnerabilty", Posting to ANSI X9F1 [K] B. Kaliski, "MQV Vulnerabilty", Posting to ANSI X9F1 and
and IEEE P1363 newsgroups, 1998. IEEE P1363 newsgroups, 1998.
[LMQSV] L. Law, A. Menezes, M. Qu, J. Solinas and S. Vanstone, [LMQSV] L. Law, A. Menezes, M. Qu, J. Solinas and S. Vanstone,
"An efficient protocol for authenticated key agreement", "An efficient protocol for authenticated key agreement",
Technical report CORR 98-05, University of Waterloo, Technical report CORR 98-05, University of Waterloo,
1998. 1998.
[CMS-KEA] J. Pawling, "CMS KEA and SKIPJACK Conventions", RFC [CMS-KEA] Pawling, J., "CMS KEA and SKIPJACK Conventions", RFC
2876, July 2000. 2876, July 2000.
[MSG] B. Ramsdell, "S/MIME Version 3 Message Specification", [MSG] Ramsdell, B., "S/MIME Version 3 Message Specification",
RFC 2633, June 1999. RFC 2633, June 1999.
[CMS-DH] E. Rescorla, "Diffie-Hellman Key Agreement Method", [CMS-DH] Rescorla, E., "Diffie-Hellman Key Agreement Method", RFC
RFC 2631, June 1999. 2631, June 1999.
[SEC1] SECG, "Elliptic Curve Cryptography", Standards for [SEC1] SECG, "Elliptic Curve Cryptography", Standards for
Efficient Cryptography Group, 2000. Available from Efficient Cryptography Group, 2000. Available from
www.secg.org/collateral/sec1.pdf. www.secg.org/collateral/sec1.pdf.
[SEC2] SECG, "Recommended Elliptic Curve Domain Parameters", [SEC2] SECG, "Recommended Elliptic Curve Domain Parameters",
Standards for Efficient Cryptography Group, 2000. Standards for Efficient Cryptography Group, 2000.
Available from www.secg.org/collateral/sec2.pdf. Available from www.secg.org/collateral/sec2.pdf.
Security Considerations Security Considerations
This specification is based on [CMS], [X9.62] and [SEC1] and the This specification is based on [CMS], [X9.62] and [SEC1] and the
appropriate security considerations of those documents apply. appropriate security considerations of those documents apply.
In addition, implementors of AuthenticatedData should be aware of In addition, implementors of AuthenticatedData should be aware of the
the concerns expressed in [BON] when using AuthenticatedData to concerns expressed in [BON] when using AuthenticatedData to send
send messages to more than one recipient. Also, users of MQV messages to more than one recipient. Also, users of MQV should be
should be aware of the vulnerability in [K]. aware of the vulnerability in [K].
When 256, 384, and 512 bit hash functions succeed SHA-1 in future 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 revisions of [FIPS], [FIPS-186-2], [X9.62] and [SEC1], then they can
can similarly succeed SHA-1 in a future revision of this document. similarly succeed SHA-1 in a future revision of this document.
Intellectual Property Rights Intellectual Property Rights
The IETF has been notified of intellectual property rights claimed The IETF has been notified of intellectual property rights claimed in
in regard to the specification contained in this document. For regard to the specification contained in this document. For more
more information, consult the online list of claimed rights information, consult the online list of claimed rights
(http://www.ietf.org/ipr.html). (http://www.ietf.org/ipr.html).
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of standards-related documentation can be found in BCP 11. Copies of
claims of rights made available for publication and any assurances claims of rights made available for publication and any assurances of
of licenses to be made available, or the result of an attempt made licenses to be made available, or the result of an attempt made to
to obtain a general license or permission for the use of such obtain a general license or permission for the use of such
proprietary rights by implementors or users of this specification proprietary rights by implementors or users of this specification can
can be obtained from the IETF Secretariat. be obtained from the IETF Secretariat.
Acknowledgments Acknowledgments
The methods described in this document are based on work done by The methods described in this document are based on work done by the
the ANSI X9F1 working group. The authors wish to extend their ANSI X9F1 working group. The authors wish to extend their thanks to
thanks to ANSI X9F1 for their assistance. The authors also wish to ANSI X9F1 for their assistance. The authors also wish to thank Peter
thank Peter de Rooij for his patient assistance. The technical de Rooij for his patient assistance. The technical comments of
comments of Francois Rousseau were valuable contributions. Francois Rousseau were valuable contributions.
Authors' Addresses Authors' Addresses
Simon Blake-Wilson Simon Blake-Wilson
Certicom Corp Certicom Corp
5520 Explorer Drive #400 5520 Explorer Drive #400
Mississauga, ON L4W 5L1 Mississauga, ON L4W 5L1
e-mail: sblakewi@certicom.com EMail: sblakewi@certicom.com
Daniel R. L. Brown Daniel R. L. Brown
Certicom Corp pCerticom Corp
5520 Explorer Drive #400 5520 Explorer Drive #400
Mississauga, ON L4W 5L1 Mississauga, ON L4W 5L1
e-mail: dbrown@certicom.com EMail: dbrown@certicom.com
Paul Lambert Paul Lambert
e-mail: plambert@sprintmail.com EMail: plambert@sprintmail.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The Internet Society (2001). All Rights Reserved. Copyright (C) The Internet Society (2002). All Rights Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain others, and derivative works that comment on or otherwise explain it
it or assist in its implementation may be prepared, copied, or assist in its implementation may be prepared, copied, published
published and distributed, in whole or in part, without restriction and distributed, in whole or in part, without restriction of any
of any kind, provided that the above copyright notice and this kind, provided that the above copyright notice and this paragraph are
paragraph are included on all such copies and derivative works. included on all such copies and derivative works. However, this
However, this document itself may not be modified in any way, such document itself may not be modified in any way, such as by removing
as by removing the copyright notice or references to the Internet the copyright notice or references to the Internet Society or other
Society or other Internet organizations, except as needed for the Internet organizations, except as needed for the purpose of
purpose of developing Internet standards in which case the developing Internet standards in which case the procedures for
procedures for copyrights defined in the Internet Standards process copyrights defined in the Internet Standards process must be
must be followed, or as required to translate it into languages followed, or as required to translate it into languages other than
other than English. English.
The limited permissions granted above are perpetual and will not be The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns. revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on This document and the information contained herein is provided on an
an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
 End of changes. 95 change blocks. 
309 lines changed or deleted 293 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/