LAMPS WG                                                   P. Kampanakis
Internet-Draft                                             Cisco Systems
Intended status: Standards Track                                 Q. Dang
Expires: August 19, December 31, 2018                                          NIST
                                                       February 15,
                                                           June 29, 2018

     Internet X.509 Public Key Infrastructure: Additional SHAKE Algorithms
                   and Algorithm
  Identifiers for RSA RSASSA-PSS and ECDSA
                     draft-ietf-lamps-pkix-shake-01 using SHAKEs as Hash Functions
                     draft-ietf-lamps-pkix-shake-02

Abstract

   Digital signatures are used to sign messages, X.509 certificates and
   CRLs (Certificate Revocation Lists).  This document describes the
   conventions for using the SHAKE family of hash functions in the
   Internet X.509 as one-way hash functions with the RSA Probabilistic
   Signature Scheme and ECDSA signature algorithms; the algorithms.  The conventions for
   the associated subject public keys are also described.  Digital
   signatures are used to sign messages, certificates and CRLs
   (Certificate Revocation Lists).

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on August 19, December 31, 2018.

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Table of Contents

   1.  Change Log  . . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Message Digest Algorithms  Identifiers . . . . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  One-way Extensible-Output-Function SHAKEs
   4.  Use in PKIX . . . . . . . .   3
     3.2.  Mask Generation SHAKEs . . . . . . . . . . . . . . . . .   4
   4.  Signature Algorithms
     4.1.  Signatures  . . . . . . . . . . . . . . . . . . . .   4
     4.1.  RSASSA-PSS with SHAKEs . . .   4
       4.1.1.  RSASSA-PSS Signatures . . . . . . . . . . . . . .   4
     4.2.  ECDSA with SHAKEs . .   5
       4.1.2.  ECDSA Signatures  . . . . . . . . . . . . . . . . . .   5
   5.
     4.2.  Public Key Algorithms Keys . . . . . . . . . . . . . . . . . . . . . . .   6
   6.  Acknowledgements
       4.2.1.  RSASSA-PSS Public Keys  . . . . . . . . . . . . . . .   6
       4.2.2.  ECDSA Public Keys . . . . . . . . . . . . . . . . . .   7
   7.
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   8.
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   9.
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     9.1.
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     9.2.
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   9
   Appendix A.  ASN.1 module . . . . . . . . . . . . . . . . . . . .   9  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9  10

1.  Change Log

   [ EDNOTE: Remove this section before publication. ]

   o  draft-ietf-lamps-pkix-shake-02:

      *  Significant reorganization of the sections to simplify the
         introduction, the new OIDs and their use in PKIX.

      *  Added new OIDs for RSASSA-PSS that hardcode hash, salt and MFG,
         according the WG consensus.

      *  Updated Public Key section to use the new RSASSA-PSS OIDs and
         clarify the algorithm identifier usage.

      *  Removed the no longer used SHAKE OIDs from section 3.1.

      *  Consolidated subsection for message digest algorithms.

      *  Text fixes.

   o  draft-ietf-lamps-pkix-shake-01:

      *  Changed titles and section names.

      *  Removed DSA after WG discussions.

      *  Updated shake OID names and parameters, added MGF1 section.

      *  Updated RSASSA-PSS section.

      *  Added Public key algorithm OIDs.

      *  Populated Introduction and IANA sections.

   o  draft-ietf-lamps-pkix-shake-00:

      *  Initial version

2.  Introduction

   This document describes several cryptographic algorithm identifiers
   for several cryptographic algorithms which may use variable length output
   SHAKE functions introduced in [SHA3] which can be used with the
   Internet X.509 Certificate and CRL profile [RFC5280].
   It describes the OIDs for variable length SHAKE algorithms introduced
   in [SHA3] and how they can be used in X.509 certificates. [ EDNOTE:
   Update here. ]

3.  Message Digest Algorithms

   This section describes two

   The SHA-3 family of one-way hash functions and digital
   signature algorithms using these functions, which may be used to sign
   certificates and CRLs, and identifies OIDs (Object Identifiers) for
   public keys contained in certificates.

3.1.  One-way Extensible-Output-Function SHAKEs

   The SHA-3 family of one-way hash functions is specified in [SHA3].
   In the SHA-3 family, two extendable-output is specified in [SHA3].
   In the SHA-3 family, two extendable-output functions, called SHAKE128
   and SHAKE256 are defined.  Four hash functions, SHA3-224, SHA3-256,
   SHA3-384, and SHA3-512 are also defined but are out of scope for this
   document.  A SHAKE is a variable length hash function.  The output
   lengths, in bits, of the SHAKE hash functions is are defined by the
   parameter d. d
   parameter.  The corresponding collision and preimage resistance
   security levels for SHAKE128 and SHAKE256 are respectively
   min(d/2,128) and min(d,128) and min(d/2,256) and min(d,256).  The
   Object Identifiers (OIDs) for these two min(d,256) bits.

   SHAKEs can be used as the message digest function (to hash the
   message to be signed) and as the hash function in the mask generating
   functions are defined in
   [shake-nist-oids] RSASSA-PSS and ECDSA.  In this document, we define four
   new OIDs for RSASSA-PSS and ECDSA when SHAKE128 and SHAKE256 are included here used
   as hash functions.  The same algorithm identifiers are used for convenience:

     id-shake128-len
   identifying a public key, and identifying a signature.

3.  Identifiers

   The new identifiers for RSASSA-PSS signatures using SHAKEs are below.

     id-RSASSA-PSS-SHAKE128  OBJECT IDENTIFIER  ::=  { TBD }
     id-RSASSA-PSS-SHAKE256  OBJECT IDENTIFIER  ::=  { TBD }

     [ EDNOTE: "TBD" will be specified by NIST later. ]

   The new algorithm identifiers of ECDSA signatures using SHAKEs are
   below.

  id-ecdsa-with-shake128 OBJECT IDENTIFIER  ::=  { joint-iso-itu-t(2) joint-iso-ccitt(2)
                        country(16) us(840) organization(1) gov(101) csor(3)
                   nistalgorithm(4) hashalgs(2) 17 algorithms(4)
                        id-ecdsa-with-shake(3) TBD }

      ShakeOutputLen ::= INTEGER -- Output length in octets

   When using the id-shake128-len algorithm identifier, the parameters
   MUST be present, and they MUST employ the ShakeOutputLen syntax that
   contains an encoded positive integer value at least 32 in this
   specification.

      id-shake256-len

  id-ecdsa-with-shake256 OBJECT IDENTIFIER  ::=  { joint-iso-itu-t(2) joint-iso-ccitt(2)
                        country(16) us(840) organization(1) gov(101) csor(3)
                   nistalgorithm(4) hashalgs(2) 18 algorithms(4)
                        id-ecdsa-with-shake(3) TBD }

      ShakeOutputLen ::= INTEGER -- Output length in octets

   When using the id-shake256-len algorithm identifier, the

  [ EDNOTE: "TBD" will be specified by NIST later. ]

   The parameters for these four identifiers above MUST be present, and they MUST employ absent.  That
   is, the ShakeOutputLen syntax that
   contains an encoded positive integer value at least 64 in this
   specification.

3.2.  Mask Generation SHAKEs

   The RSASSA-PSS signature algorithm uses a mask generation function.
   A mask generation function takes an octet string of variable length
   and identifier SHALL be a desired output length as input, and outputs an octet string SEQUENCE of one component, the desired length.  The mask generation function used OID.

4.  Use in RSASSA-PSS
   is defined PKIX

4.1.  Signatures

   Signatures can be placed in [RFC8017], but we include it here as well a number of different ASN.1 structures.
   The top level structure for
   convenience:

      id-mgf1  OBJECT IDENTIFIER an X.509 certificate, to illustrate how
   signatures are frequently encoded with an algorithm identifier and a
   location for the signature, is

      Certificate  ::=  SEQUENCE  { pkcs-1 8
         tbsCertificate       TBSCertificate,
         signatureAlgorithm   AlgorithmIdentifier,
         signatureValue       BIT STRING  }

   The parameters field associated with id-mgf1 MUST have a
   hashAlgorithm value that identifies the hash identifiers defined in Section 3 can be used with MGF1.  To use
   SHAKE as this hash, this parameter the
   AlgorithmIdentifier in the signatureAlgorithm field in the sequence
   Certificate and the signature field in the sequence tbsCertificate in
   X.509 [RFC3280].

   Conforming CA implementations MUST be id-shake128-len or id-
   shake256-len as specify the algorithms explicitly
   by using the OIDs specified in Section 3.1 above.

4.  Signature Algorithms

4.1. 3 when encoding RSASSA-PSS and
   ECDSA with SHAKEs

   The RSASSA-PSS signature algorithm identifier SHAKE signatures, and its parameters are
   specifed public keys in [RFC4055]:

      id-RSASSA-PSS  OBJECT IDENTIFIER  ::=  { pkcs-1 10 }

      RSASSA-PSS-params  ::=  SEQUENCE  {
            hashAlgorithm      HashAlgorithm,
            maskGenAlgorithm   MaskGenAlgorithm,
            saltLength         INTEGER,
            trailerField       INTEGER }

   This document adds two new hash algorithm choices certificates and two new choices
   CRLs.  Encoding rules for mask generation functions.  These RSASSA-PSS and ECDSA signature values are the SHAKE128
   specified in [RFC4055] and SHAKE256 [RFC5480] respectively.

   Conforming client implementations that process RSASSA-PSS and ECDSA
   with SHAKE signatures when processing certificates and CRLs MUST
   recognize the corresponding OIDs.

4.1.1.  RSASSA-PSS Signatures

   The RSASSA-PSS algorithm identifiers specified is defined in Section 3.1. [RFC8017].  When SHAKE128 id-RSASSA-
   PSS-SHAKE128 or SHAKE256 id-RSASSA-PSS-SHAKE256 specified in Section 3 is used as
   used, the hashAlgorithm, it encoding MUST also omit the parameters field.  That is, the
   AlgorithmIdentifier SHALL be used as a SEQUENCE of one component, id-RSASSA-
   PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256.

   The hash algorithm to hash a message being signed and the maskGenAlgorithm.

   When used as hash
   algorithm in the hashAlgorithm, maskGenAlgorithm used in RSASSA-PSS MUST be the
   same, SHAKE128 or SHAKE256 output-
   length must respectively.  The output-length of the
   hash algorithm which hashes the message SHALL be either 32 or 64 bytes
   respectively.  In these cases,
   the parameters MUST be present, and they MUST employ

   The maskGenAlgorithm is the
   ShakeOutputLen syntax that contains an encoded positive integer value MGF1 specified in Section B.2.1 of 32 or 64
   [RFC8017].  The output length for id-shake128-len or id-shake256-len algorithm
   identifier respectively.

   When id-shake128-len SHAKE128 or id-shake256-len algorithm identifier is SHAKE256 being used as
   the id-mfg1 maskGenAlgorithm parameter, the ShakeOutputLen
   parameter must be hash function in MGF1 is (n - 264)/8 or (n - 520)/8 respectively for
   SHAKE128 and SHAKE256, bytes
   respectively, where n is the RSA modulus in bits.  For example, when
   RSA modulus n is 2048, ShakeOutputLen must the output length of SHAKE128 or SHAKE256 in
   the MGF1 will be 223 or 191 when id-shake128-len id-RSASSA-PSS-SHAKE128 or id-shake256-len id-RSASSA-
   PSS-SHAKE256 is are used respectively.

   The parameter RSASSA-PSS saltLength MUST be 32 or 64 bytes respectively for respectively.
   Finally, the
   SHAKE128 and SHA256 OIDs.

4.2.  ECDSA trailerField MUST be 1, which represents the trailer
   field with SHAKEs hexadecimal value 0xBC [RFC8017].

4.1.2.  ECDSA Signatures

   The Elliptic Curve Digital Signature Algorithm (ECDSA) is defined in
   "Public Key Cryptography for the Financial Services Industry: The
   Elliptic Curve Digital Signature Standard (ECDSA)"
   [X9.62].  The
   ASN.1 OIDs of ECDSA signature algorithms using SHAKE128 and SHAKE256,
   are below:

   id-ecdsa-with-shake128 OBJECT IDENTIFIER  ::=  { joint-iso-ccitt(2)
                        country(16) us(840) organization(1) gov(101) csor(3) algorithms(4)
                        id-ecdsa-with-shake(3) x }

   id-ecdsa-with-shake256 OBJECT IDENTIFIER  ::=  { joint-iso-ccitt(2)
                        country(16) us(840) organization(1) gov(101) csor(3) algorithms(4)
                        id-ecdsa-with-shake(3) y }

   [ EDNOTE: "x" and "y" will be specified by NIST later. ]  When the id-ecdsa-with-SHAKE128 or id-ecdsa-with-SHAKE256, id-ecdsa-with-SHAKE256
   (specified in Section 3) algorithm identifier appears in appears, the algorithm field respective
   SHAKE function (SHAKE128 or SHAKE256) is used as an AlgorithmIdentifier, the hash.  The
   encoding MUST omit the parameters field.  That is, the
   AlgorithmIdentifier SHALL be a SEQUENCE of one component, the OID id-
   ecdsa-with-SHAKE128 or ecdsa-with-SHAKE256.

   Conforming CA implementations MUST specify the hash algorithm
   explicitly using the OIDs specified in Section 3.2 above when
   encoding ECDSA/SHAKE signatures in certificates id-ecdsa-with-SHAKE256.

   For simplicity and CRLs.

   Conforming client implementations that process ECDSA signatures compliance with
   any the ECDSA standard specification,
   the output size of the SHAKE hash algorithms when processing certificates and
   CRLs MUST recognize the corresponding OIDs specified in Sections 3.1
   and 3.2 above.

   Encoding rules function must be explicitly determined.
   The output size, d, for ECDSA signature values are specified SHAKE128 or SHAKE256 used in [RFC4055],
   Section 2.2.3, and [RFC5480]. ECDSA MUST be
   256 or 512 bits respectively.

   Conforming CA implementations that generate ECDSA with SHAKE
   signatures in certificates or CRLs MUST generate such ECDSA signatures in
   accordance with all the requirements specified in Sections 7.2 and
   7.3 of [X9.62] or with all the requirements specified in
   Section 4.1.3 of [SEC1].  They MAY also generate such ECDSA signatures in
   accordance with all the recommendations in [X9.62] or [SEC1] if they
   have a stated policy that requires conformance to these standards.
   These standards above may have not specified SHAKE128 and SHAKE256 as hash
   algorithm options.  However, SHAKE128 and SHAKE256 with output length
   being 32 and 64 octets respectively are subtitutions for 256 and
   512-bit output hash algorithms such as SHA256 and SHA512 used in the
   standards.

5.

4.2.  Public Key Algorithms Keys

   Certificates conforming to [RFC5280] can convey a public key for any
   public key algorithm.  The certificate indicates the algorithm
   through an algorithm identifier.  This algorithm identifier is an OID
   and optionally associated parameters.

   In the X.509 certificate, the subjectPublicKeyInfo field has the
   SubjectPublicKeyInfo type, which has the following ASN.1 syntax:

     SubjectPublicKeyInfo  ::=  SEQUENCE  {
          algorithm         AlgorithmIdentifier,
          subjectPublicKey  BIT STRING
     }

   The fields in SubjectPublicKeyInfo have the following meanings:

   o  algorithm is the algorithm identifier and parameters for the
      public key.

   o  subjectPublicKey contains the byte stream of the public key.  The
      algorithms defined in this document always encode the public key
      as an exact multiple of 8-bits.

   The conventions for RSA RSASSA-PSS and ECDSA public keys algorithm
   identifiers are as specified in [RFC3279], [RFC4055] and [RFC5480].  We [RFC5480] ,
   but we include them here below for convenience.

4.2.1.  RSASSA-PSS Public Keys

   [RFC3279] defines the following OID for RSA AlgorithmIdentifier in
   the SubjectPublicKeyInfo with NULL parameters.

     rsaEncryption OBJECT IDENTIFIER ::=  { pkcs-1 1}

   Additionally, [RFC4055] adds when the RSA private key owner wishes to limit the use
   of the corresponding RSASSA-PSS OID public key exclusively to RSASSA-PSS, the AlgorithmIdentifiers
   for RSASSA-PSS defined in Section 3 can be used as the algorithm
   field in the SubjectPublicKeyInfo sequence [RFC3280].  The identifier and parameters (also shown
   parameters, as explained in section Section 4 3, MUST be absent.

   Regardless of this
   document).  The parameters may what public key algorithm identifier is used, the RSA
   public key, which is composed of a modulus and a public exponent,
   MUST be either absent or present when
   RSASSA-PSS OID encoded using the RSAPublicKey type [RFC4055].  The output of
   this encoding is used as subject public key information.

      id-RSASSA-PSS  OBJECT IDENTIFIER carried in the certificate subjectPublicKey.

     RSAPublicKey ::= SEQUENCE { pkcs-1 10
           modulus INTEGER, -- n
           publicExponent INTEGER  -- e
     }

   If id-RSASSA-PSS

4.2.2.  ECDSA Public Keys

   For ECDSA, when id-ecdsa-with-shake128 or id-ecdsa-with-shake256 is
   used in the public key identifier with
   parameters, Section 3.3 of [RFC4055] describes that the signature
   algorithm parameters MUST match as the parameters AlgorithmIdentifier in the key structure algorithm identifier except the saltLength field.  The saltLength field in of
   SubjectPublicKeyInfo, the signature parameters parameters, as explained in section
   Section 3, MUST be greater or equal to that in
   the key parameters field.  If the id-RSASSA-PSS parameters are NULL
   no further parameter validation is necessary.

   For ECDSA, [RFC5480] defines absent.

   Additionally, the mandatory EC public key identifier SubjectPublicKey is defined in
   Section 2.1.1 and its
   parameters as syntax is in Section 2.2 of [RFC5480].  We also
   include them here for convenience:

     id-ecPublicKey OBJECT IDENTIFIER ::= {
          iso(1) member-body(2) us(840) ansi-X9-62(10045) keyType(2) 1 }

   The id-ecPublicKey parameters MUST be present and are defined as

     ECParameters ::= CHOICE {
         namedCurve         OBJECT IDENTIFIER
         -- implicitCurve   NULL
         -- specifiedCurve  SpecifiedECDomain
      }

   The ECParameters associated with the ECDSA public key in the signer's
   certificate SHALL apply to the verification of the signature.

6.  Acknowledgements

   We would like to thank Sean Turner for his valuable contributions to
   this document.

7.

5.  IANA Considerations

   This document uses several new registries that were originally created in
   [shake-nist-oids].  No further registries are required. [ EDNOTE: Update here. ]

8.

6.  Security Considerations

   SHAKE128 and SHAKE256 are one-way extensible-output functions.  Their
   output length depends on a required length of the consumming
   application.

   The SHAKEs are deterministic functions.  Like any other deterministic
   functions, executing each function with the same input multiple times
   will produce the same output.  Therefore, users should not expect
   unrelated outputs (with the same or different output lengths) from
   excuting a SHAKE function with the same input multiple times.

   Implementations must protect the signer's private key.  Compromise of
   the signer's private key permits masquerade.

   When more than two parties share the same message-authentication key,
   data origin authentication is not provided.  Any party that knows the
   message-authentication key can compute a valid MAC, therefore the
   content could originate from any one of the parties.

   Implementations must randomly generate message-authentication keys
   and one-time values, such as the k
   value when generating a ECDSA signature.  In addition, the generation
   of public/private key pairs relies on random numbers.  The use of
   inadequate pseudo-random number generators (PRNGs) to generate such
   cryptographic values can result in little or no security.  The
   generation of quality random numbers is difficult.  [RFC4086] offers
   important guidance in this area, and [SP800-90A] series provide
   acceptable PRNGs.

   Implementers should be aware that cryptographic algorithms may become
   weaker with time.  As new cryptanalysis techniques are developed and
   computing performance improves, power increases, the work factor or time required to break
   a particular cryptographic algorithm will reduce. may decrease.  Therefore,
   cryptographic algorithm implementations should be modular allowing
   new algorithms to be readily inserted.  That is, implementers should
   be prepared to regularly update the set of algorithms in their
   implementations.

9.

7.  Acknowledgements

   We would like to thank Sean Turner for his valuable contributions to
   this document.

8.  References

9.1.

8.1.  Normative References

   [RFC3279]  Bassham, L.,

   [RFC3280]  Housley, R., Polk, W., Ford, W., and R. Housley, "Algorithms and
              Identifiers for the Internet D. Solo, "Internet
              X.509 Public Key Infrastructure Certificate and
              Certificate Revocation List (CRL) Profile", RFC 3279, 3280,
              DOI 10.17487/RFC3279, 10.17487/RFC3280, April 2002, <https://www.rfc-editor.org/info/rfc3279>.
              <https://www.rfc-editor.org/info/rfc3280>.

   [RFC4055]  Schaad, J., Kaliski, B., and R. Housley, "Additional
              Algorithms and Identifiers for RSA Cryptography for use in
              the Internet X.509 Public Key Infrastructure Certificate
              and Certificate Revocation List (CRL) Profile", RFC 4055,
              DOI 10.17487/RFC4055, June 2005,
              <https://www.rfc-editor.org/info/rfc4055>.

   [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
              Housley, R., and W. Polk, "Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
              <https://www.rfc-editor.org/info/rfc5280>.

   [RFC5480]  Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk,
              "Elliptic Curve Cryptography Subject Public Key
              Information", RFC 5480, DOI 10.17487/RFC5480, March 2009,
              <https://www.rfc-editor.org/info/rfc5480>.

   [RFC8017]  Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch,
              "PKCS #1: RSA Cryptography Specifications Version 2.2",
              RFC 8017, DOI 10.17487/RFC8017, November 2016,
              <https://www.rfc-editor.org/info/rfc8017>.

   [SHA3]     National Institute of Standards and Technology, "SHA-3
              Standard - Permutation-Based Hash and Extendable-Output
              Functions FIPS PUB 202", August 2015,
              <https://www.nist.gov/publications/sha-3-standard-
              permutation-based-hash-and-extendable-output-functions>.

9.2.

8.2.  Informative References

   [RFC3279]  Bassham, L., Polk, W., and R. Housley, "Algorithms and
              Identifiers for the Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 3279, DOI 10.17487/RFC3279, April
              2002, <https://www.rfc-editor.org/info/rfc3279>.

   [RFC4086]  Eastlake 3rd, D., Schiller, J., and S. Crocker,
              "Randomness Requirements for Security", BCP 106, RFC 4086,
              DOI 10.17487/RFC4086, June 2005,
              <https://www.rfc-editor.org/info/rfc4086>.

   [SEC1]     Standards for Efficient Cryptography Group, "SEC 1:
              Elliptic Curve Cryptography", May 2009,
              <http://www.secg.org/sec1-v2.pdf>.

   [shake-nist-oids]
              National Institute of Standards and Technology, "Computer
              Security Objects Register", October 2017,
              <https://csrc.nist.gov/Projects/Computer-Security-Objects-
              Register/Algorithm-Registration>.

   [SP800-90A]
              National Institute of Standards and Technology,
              "Recommendation for Random Number Generation Using
              Deterministic Random Bit Generators. NIST SP 800-90A",
              June 2015,
              <http://nvlpubs.nist.gov/nistpubs/SpecialPublications/
              NIST.SP.800-90Ar1.pdf>.

   [X9.62]    American National Standard for Financial Services (ANSI),
              "X9.62-2005 Public Key Cryptography for the Financial
              Services Industry: The Elliptic Curve Digital Signature
              Standard (ECDSA)", November 2005.

Appendix A.  ASN.1 module

   [ EDNOTE: More here. ]

Authors' Addresses

   Panos Kampanakis
   Cisco Systems

   Email: pkampana@cisco.com

   Quynh Dang
   NIST
   100 Bureau Drive, Stop 8930
   Gaithersburg, MD  20899-8930
   USA

   Email: quynh.dang@nist.gov