Use of ML-KEM in the Cryptographic Message Syntax (CMS)
draft-ietf-lamps-cms-kyber-05

LAMPS                                                            J. Prat
Internet-Draft                                       CryptoNext Security
Intended status: Standards Track                            M. Ounsworth
Expires: 18 April 2025                                           Entrust
                                                            D. Van Geest
                                                     CryptoNext Security
                                                         15 October 2024

        Use of ML-KEM in the Cryptographic Message Syntax (CMS)
                     draft-ietf-lamps-cms-kyber-05

Abstract

   The Module-Lattice-based Key-Encapsulation Mechanism (ML-KEM)
   algorithm is a one-pass (store-and-forward) cryptographic mechanism
   for an originator to securely send keying material to a recipient
   using the recipient's ML-KEM public key.  Three parameters sets for
   the ML-KEM algorithm are specified by NIST in [FIPS203].  In order of
   increasing security strength (and decreasing performance), these
   parameter sets are ML-KEM-512, ML-KEM-768, and ML-KEM-1024.  This
   document specifies the conventions for using ML-KEM with the
   Cryptographic Message Syntax (CMS) using KEMRecipientInfo as
   specified in [RFC9629].

About This Document

   This note is to be removed before publishing as an RFC.

   Status information for this document may be found at
   https://datatracker.ietf.org/doc/draft-ietf-lamps-cms-kyber/.

   Discussion of this document takes place on the Limited Additional
   Mechanisms for PKIX and SMIME (lamps) Working Group mailing list
   (mailto:spasm@ietf.org), which is archived at
   https://mailarchive.ietf.org/arch/browse/spasm/.  Subscribe at
   https://www.ietf.org/mailman/listinfo/spasm/.

   Source for this draft and an issue tracker can be found at
   https://github.com/lamps-wg/kyber-certificates.

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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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Conventions and Terminology . . . . . . . . . . . . . . .   3
     1.2.  ML-KEM  . . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Use of the ML-KEM Algorithm in CMS  . . . . . . . . . . . . .   4
     2.1.  RecipientInfo Conventions . . . . . . . . . . . . . . . .   4
     2.2.  Underlying Components . . . . . . . . . . . . . . . . . .   5
       2.2.1.  Use of the HKDF-based Key Derivation Function . . . .   5
       2.2.2.  Components for ML-KEM in CMS  . . . . . . . . . . . .   6
     2.3.  Certificate Conventions . . . . . . . . . . . . . . . . .   7
     2.4.  SMIME Capabilities Attribute Conventions  . . . . . . . .   7
   3.  Identifiers . . . . . . . . . . . . . . . . . . . . . . . . .   7
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Appendix A.  ASN.1 Module . . . . . . . . . . . . . . . . . . . .  13
   Appendix B.  ML-KEM CMS Enveloped-Data Example  . . . . . . . . .  15
     B.1.  Originator CMS Processing . . . . . . . . . . . . . . . .  15

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     B.2.  Recipient CMS Processing  . . . . . . . . . . . . . . . .  18
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  20

1.  Introduction

   ML-KEM is an IND-CCA2-secure key-encapsulation mechanism (KEM)
   standardized in [FIPS203] by the US NIST PQC Project [NIST-PQ].
   Prior to standardization, the algorithm was known as Kyber.  ML-KEM
   and Kyber are not compatible.

   Native support for Key Encapsulation Mechanisms (KEMs) was added to
   CMS in [RFC9629], which defines the KEMRecipientInfo structure for
   the use of KEM algorithms for the CMS enveloped-data content type,
   the CMS authenticated-data content type, and the CMS authenticated-
   enveloped-data content type.  This document specifies the direct use
   of ML-KEM in the KEMRecipientInfo structure in CMS using each of the
   three parameter sets from [FIPS203], namely MK-KEM-512, ML-KEM-768,
   and ML-KEM-1024.  It does not address or preclude the use of ML-KEM
   as part of any hybrid scheme.

1.1.  Conventions and Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.2.  ML-KEM

   ML-KEM is a lattice-based key encapsulation mechanism using Module
   Learning with Errors as its underlying primitive, which is a
   structured lattices variant that offers good performance and
   relatively small and balanced key and ciphertext sizes.  ML-KEM was
   standardized with three parameter sets: ML-KEM-512, ML-KEM-768, and
   ML-KEM-1024.  The parameters for each of the security levels were
   chosen to be at least as secure as a generic block cipher of 128,
   192, or 256 bits, respectively.

   Like all KEM algorithms, ML-KEM provides three functions: KeyGen(),
   Encapsulate(), and Decapsulate().

   KeyGen() -> (pk, sk):  Generate the public key (pk) and a private key
      (sk).

   Encapsulate(pk) -> (ct, ss):  Given the recipient's public key (pk),
      produce a ciphertext (ct) to be passed to the recipient and a
      shared secret (ss) for use by the originator.

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   Decapsulate(sk, ct) -> ss:  Given the private key (sk) and the
      ciphertext (ct), produce the shared secret (ss) for the recipient.

   The KEM functions defined above correspond to the following functions
   in [FIPS203]:

   KeyGen():  ML-KEM.KeyGen() from section 7.1.

   Encapsulate():  ML-KEM.Encaps() from section 7.2.

   Decapsulate():  ML-KEM.Decaps() from section 7.3.

   All security levels of ML-KEM use SHA3-256, SHA3-512, SHAKE256, and
   SHAKE512 internally.

2.  Use of the ML-KEM Algorithm in CMS

   The ML-KEM algorithm MAY be employed for one or more recipients in
   the CMS enveloped-data content type [RFC5652], the CMS authenticated-
   data content type [RFC5652], or the CMS authenticated-enveloped-data
   content type [RFC5083].  In each case, the KEMRecipientInfo [RFC9629]
   is used with the ML-KEM algorithm to securely transfer the content-
   encryption key from the originator to the recipient.

   Processing ML-KEM with KEMRecipientInfo follows the same steps as
   Section 2 of [RFC9629].  To support the ML-KEM algorithm, a CMS
   originator MUST implement the Encapsulate() function and a CMS
   responder MUST implement the Decapsulate() function.

2.1.  RecipientInfo Conventions

   When the ML-KEM algorithm is employed for a recipient, the
   RecipientInfo alternative for that recipient MUST be
   OtherRecipientInfo using the KEMRecipientInfo structure as defined in
   [RFC9629].

   The fields of the KEMRecipientInfo MUST have the following values:

      version is the syntax version number; it MUST be 0.

      rid identifies the recipient's certificate or public key.

      kem identifies the KEM algorithm; it MUST contain one of id-alg-
      ml-kem-512, id-alg-ml-kem-768, or id-alg-ml-kem-1024.  These
      identifiers are reproduced in Section 3.

      kemct is the ciphertext produced for this recipient.

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      kdf identifies the key-derivation algorithm.  Note that the Key
      Derivation Function (KDF) used for CMS RecipientInfo process MAY
      be different than the KDF used within the ML-KEM algorithm.

      kekLength is the size of the key-encryption key in octets.

      ukm is an optional random input to the key-derivation function.
      ML-KEM doesn't place any requirements on the ukm contents.

      wrap identifies a key-encryption algorithm used to encrypt the
      content-encryption key.

2.2.  Underlying Components

   When ML-KEM is employed in CMS, the security levels of the different
   underlying components used within the KEMRecipientInfo structure
   SHOULD be consistent.

2.2.1.  Use of the HKDF-based Key Derivation Function

   The HMAC-based Extract-and-Expand Key Derivation Function (HKDF) is
   defined in [RFC5869].

   The HKDF function is a composition of the HKDF-Extract and HKDF-
   Expand functions.

   HKDF(salt, IKM, info, L)
     = HKDF-Expand(HKDF-Extract(salt, IKM), info, L)

   HKDF(salt, IKM, info, L) takes the following parameters:

   salt:  optional salt value (a non-secret random value).  In this
      document this parameter is unused, that is it is the zero-length
      string "".

   IKM:  input keying material.  In this document this is the shared
      secret outputted from the Encapsulate() or Decapsulate()
      functions.  This corresponds to the IKM KDF input from Section 5
      of [RFC9629].

   info:  optional context and application specific information.  In
      this document this corresponds to the info KDF input from
      Section 5 of [RFC9629].  This is the ASN.1 DER encoding of
      CMSORIforKEMOtherInfo.

   L:  length of output keying material in octets.  This corresponds to

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      the L KDF input from Section 5 of [RFC9629], which is identified
      in the kekLength value from KEMRecipientInfo.  Implementations
      MUST confirm that this value is consistent with the key size of
      the key-encryption algorithm.

   HKDF may be used with different hash functions, including SHA-256
   [FIPS180].  The object identifier id-alg-hkdf-with-sha256 is defined
   in [RFC8619], and specifies the use of HKDF with SHA-256.  The
   parameter field MUST be absent when this algorithm identifier is used
   to specify the KDF for ML-KEM in KemRecipientInfo.

2.2.2.  Components for ML-KEM in CMS

   A compliant implementation MUST support HKDF with SHA-256, using the
   id-alg-hkdf-with-sha256 KDF object identifier, as the
   KemRecipientInfo KDF for all ML-KEM parameter sets.  Note that the
   KDF used to process the KEMRecipientInfo structure MAY be different
   from the KDF used in the ML-KEM algorithm.

   For ML-KEM-512, an implementation must support the AES-Wrap-128
   [RFC3394] key-encryption algorithm using the id-aes128-wrap key-
   encryption algorithm object identifier [RFC3565].

   For ML-KEM-768 and ML-KEM-1024, an implementation must support the
   AES-Wrap-256 [RFC3394] key-encryption algorithm using the id-
   aes256-wrap key-encryption algorithm object identifier [RFC3565].

   The above object identifiers are reproduced for convenience in
   Section 3.

   An implementation MAY also support other key-derivation functions and
   other key-encryption algorithms.

   If underlying components other than those specified above are used,
   then the following KDF requirements are in effect in addition to
   those asserted in [RFC9629]:

      ML-KEM-512 SHOULD be used with a KDF capable of outputting a key
      with at least 128 bits of preimage strength and with a key
      wrapping algorithm with a key length of at least 128 bits.

      ML-KEM-768 SHOULD be used with a KDF capable of outputting a key
      with at least 192 bits of preimage strength and with a key
      wrapping algorithm with a key length of at least 192 bits.

      ML-KEM-1024 SHOULD be used with a KDF capable of outputting a key
      with at least 256 bits of preimage strength and with a key
      wrapping algorithm with a key length of at least 256 bits.

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2.3.  Certificate Conventions

   The conventions specified in this section augment [RFC5280].

   A recipient who employs the ML-KEM algorithm with a certificate MUST
   identify the public key in the certificate using the id-alg-ml-kem-
   512, id-alg-ml-kem-768, or id-alg-ml-kem-1024 object identifiers
   following the conventions specified in
   [I-D.ietf-lamps-kyber-certificates].

   In particular, the key usage certificate extension MUST only contain
   keyEncipherment (Section 4.2.1.3 of [RFC5280]).

2.4.  SMIME Capabilities Attribute Conventions

   Section 2.5.2 of [RFC8551] defines the SMIMECapabilities attribute to
   announce a partial list of algorithms that an S/MIME implementation
   can support.  When constructing a CMS signed-data content type
   [RFC5652], a compliant implementation MAY include the
   SMIMECapabilities attribute that announces support for one or more of
   the ML-KEM algorithm identifiers.

   The SMIMECapability SEQUENCE representing the ML-KEM algorithm MUST
   include one of the ML-KEM object identifiers in the capabilityID
   field.  When the one of the ML-KEM object identifiers appears in the
   capabilityID field, the parameters MUST NOT be present.

3.  Identifiers

   All identifiers used to indicate ML-KEM within CMS are defined
   elsewhere but reproduced here for convenience:

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     nistAlgorithms OBJECT IDENTIFIER ::= { joint-iso-ccitt(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) }
     kems OBJECT IDENTIFIER ::= { nistAlgorithms 4 }

     id-alg-ml-kem-512 OBJECT IDENTIFIER ::= { kems 1 }

     id-alg-ml-kem-768 OBJECT IDENTIFIER ::= { kems 2 }

     id-alg-ml-kem-1024 OBJECT IDENTIFIER ::= { kems 3 }

     hashAlgs OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
         us(840) organization(1) gov(101) csor(3) nistAlgorithm(4) 2 }

     id-alg-hkdf-with-sha256 OBJECT IDENTIFIER ::= { iso(1)
         member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
         smime(16) alg(3) 28 }

     aes OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840)
         organization(1) gov(101) csor(3) nistAlgorithms(4) 1 }

     id-aes128-wrap OBJECT IDENTIFIER ::= { aes 5 }
     id-aes256-wrap OBJECT IDENTIFIER ::= { aes 45 }

4.  Security Considerations

   The Security Considerations sections of
   [I-D.ietf-lamps-kyber-certificates] and [RFC9629] apply to this
   specification as well.

   The ML-KEM variant and the underlying components need to be selected
   consistent with the desired security level.  Several security levels
   have been identified in NIST SP 800-57 Part 1 [NIST.SP.800-57pt1r5].
   To achieve 128-bit security, ML-KEM-512 SHOULD be used, the key-
   derivation function SHOULD provide at least 128 bits of preimage
   strength, and the symmetric key-encryption algorithm SHOULD have a
   security strength of at least 128 bits.  To achieve 192-bit security,
   ML-KEM-768 SHOULD be used, the key-derivation function SHOULD provide
   at least 192 bits of preimage strength, and the symmetric key-
   encryption algorithm SHOULD have a security strength of at least 192
   bits.  In the case of AES Key Wrap, a 256-bit key is typically used
   because AES-192 is not as commonly deployed.  To achieve 256-bit
   security, ML-KEM-1024 SHOULD be used, the key-derivation function
   SHOULD provide at least 256 bits of preimage strength, and the
   symmetric key-encryption algorithm SHOULD have a security strength of
   at least 256 bits.

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   Provided all inputs are well-formed, the key establishment procedure
   of ML-KEM will never explicitly fail.  Specifically, the ML-
   KEM.Encaps and ML-KEM.Decaps algorithms from [FIPS203] will always
   output a value with the same data type as a shared secret key, and
   will never output an error or failure symbol for well-formed inputs.
   However, it is possible (though extremely unlikely) that the process
   will fail in the sense that ML-KEM.Encaps and ML-KEM.Decaps will
   produce different outputs, even though both of them are behaving
   honestly and no adversarial interference is present.  In this case,
   the sender and recipient clearly did not succeed in producing a
   shared secret key.  This event is called a decapsulation failure.
   Estimates for the decapsulation failure probability (or rate) for
   each of the ML-KEM parameter sets are provided in Table 1 of
   [FIPS203] and reproduced here in Table 1.

              +===============+============================+
              | Parameter set | Decapsulation failure rate |
              +===============+============================+
              | ML-KEM-512    | 2^(-138.8)                 |
              +---------------+----------------------------+
              | ML-KEM-768    | 2^(-164.8)                 |
              +---------------+----------------------------+
              | ML-KEM-1024   | 2^(-174.8)                 |
              +---------------+----------------------------+

               Table 1: ML-KEM decapsulation failure rates

   Implementations MUST protect the ML-KEM private key, the key-
   encryption key, the content-encryption key, message-authentication
   key, and the content-authenticated-encryption key.  Disclosure of the
   ML-KEM private key could result in the compromise of all messages
   protected with that key.  Disclosure of the key-encryption key, the
   content-encryption key, or the content-authenticated-encryption key
   could result in compromise of the associated encrypted content.
   Disclosure of the key-encryption key, the message-authentication key,
   or the content-authenticated-encryption key could allow modification
   of the associated authenticated content.

   Additional considerations related to key management may be found in
   [NIST.SP.800-57pt1r5].

   The security of the ML-KEM algorithm depends on a quality random
   number generator.  For further discussion on random number
   generation, see [RFC4086].

   ML-KEM encapsulation and decapsulation only outputs a shared secret
   and ciphertext.  Implementations SHOULD NOT use intermediate values
   directly for any purpose.

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   Implementations SHOULD NOT reveal information about intermediate
   values or calculations, whether by timing or other "side channels",
   otherwise an opponent may be able to determine information about the
   keying data and/or the recipient's private key.  Although not all
   intermediate information may be useful to an opponent, it is
   preferable to conceal as much information as is practical, unless
   analysis specifically indicates that the information would not be
   useful to an opponent.

   Generally, good cryptographic practice employs a given ML-KEM key
   pair in only one scheme.  This practice avoids the risk that
   vulnerability in one scheme may compromise the security of the other,
   and may be essential to maintain provable security.

   Parties MAY gain assurance that implementations are correct through
   formal implementation validation, such as the NIST Cryptographic
   Module Validation Program (CMVP) [CMVP].

5.  IANA Considerations

   For the ASN.1 Module in Appendix A, IANA is requested to assign an
   object identifier (OID) for the module identifier (TBD1) with a
   Description of "id-mod-cms-ml-kem-2024".  The OID for the module
   should be allocated in the "SMI Security for S/MIME Module
   Identifier" registry (1.2.840.113549.1.9.16.0).

6.  Acknowledgements

   This document borrows heavily from [I-D.ietf-lamps-rfc5990bis],
   [FIPS203], and [I-D.kampanakis-ml-kem-ikev2].  Thanks go to the
   authors of those documents.  "Copying always makes things easier and
   less error prone" - RFC8411.

   Thanks to Carl Wallace and Jonathan Hammel for the detailed review
   and Carl Wallace for interoperability testing.

7.  References

7.1.  Normative References

   [FIPS203]  National Institute of Standards and Technology (NIST),
              "Module-Lattice-based Key-Encapsulation Mechanism
              Standard", FIPS PUB 203 , 13 August 2024,
              <https://doi.org/10.6028/NIST.FIPS.203>.

   [I-D.ietf-lamps-kyber-certificates]
              Turner, S., Kampanakis, P., Massimo, J., and B.
              Westerbaan, "Internet X.509 Public Key Infrastructure -

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              Algorithm Identifiers for Module-Lattice-Based Key-
              Encapsulation Mechanism (ML-KEM)", Work in Progress,
              Internet-Draft, draft-ietf-lamps-kyber-certificates-04, 20
              September 2024, <https://datatracker.ietf.org/doc/html/
              draft-ietf-lamps-kyber-certificates-04>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC3394]  Schaad, J. and R. Housley, "Advanced Encryption Standard
              (AES) Key Wrap Algorithm", RFC 3394, DOI 10.17487/RFC3394,
              September 2002, <https://www.rfc-editor.org/rfc/rfc3394>.

   [RFC3565]  Schaad, J., "Use of the Advanced Encryption Standard (AES)
              Encryption Algorithm in Cryptographic Message Syntax
              (CMS)", RFC 3565, DOI 10.17487/RFC3565, July 2003,
              <https://www.rfc-editor.org/rfc/rfc3565>.

   [RFC5083]  Housley, R., "Cryptographic Message Syntax (CMS)
              Authenticated-Enveloped-Data Content Type", RFC 5083,
              DOI 10.17487/RFC5083, November 2007,
              <https://www.rfc-editor.org/rfc/rfc5083>.

   [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/rfc/rfc5280>.

   [RFC5652]  Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
              RFC 5652, DOI 10.17487/RFC5652, September 2009,
              <https://www.rfc-editor.org/rfc/rfc5652>.

   [RFC5869]  Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand
              Key Derivation Function (HKDF)", RFC 5869,
              DOI 10.17487/RFC5869, May 2010,
              <https://www.rfc-editor.org/rfc/rfc5869>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

   [RFC8551]  Schaad, J., Ramsdell, B., and S. Turner, "Secure/
              Multipurpose Internet Mail Extensions (S/MIME) Version 4.0
              Message Specification", RFC 8551, DOI 10.17487/RFC8551,
              April 2019, <https://www.rfc-editor.org/rfc/rfc8551>.

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   [RFC8619]  Housley, R., "Algorithm Identifiers for the HMAC-based
              Extract-and-Expand Key Derivation Function (HKDF)",
              RFC 8619, DOI 10.17487/RFC8619, June 2019,
              <https://www.rfc-editor.org/rfc/rfc8619>.

   [RFC9629]  Housley, R., Gray, J., and T. Okubo, "Using Key
              Encapsulation Mechanism (KEM) Algorithms in the
              Cryptographic Message Syntax (CMS)", RFC 9629,
              DOI 10.17487/RFC9629, August 2024,
              <https://www.rfc-editor.org/rfc/rfc9629>.

7.2.  Informative References

   [CMVP]     National Institute of Standards and Technology,
              "Cryptographic Module Validation Program", 2016,
              <https://csrc.nist.gov/projects/cryptographic-module-
              validation-program>.

   [FIPS180]  Dang, Q. H. and NIST, "Secure Hash Standard", NIST Federal
              Information Processing Standards Publications 180-4,
              DOI 10.6028/NIST.FIPS.180-4, July 2015,
              <https://nvlpubs.nist.gov/nistpubs/FIPS/
              NIST.FIPS.180-4.pdf>.

   [I-D.ietf-lamps-rfc5990bis]
              Housley, R. and S. Turner, "Use of the RSA-KEM Algorithm
              in the Cryptographic Message Syntax (CMS)", Work in
              Progress, Internet-Draft, draft-ietf-lamps-rfc5990bis-10,
              30 July 2024, <https://datatracker.ietf.org/doc/html/
              draft-ietf-lamps-rfc5990bis-10>.

   [I-D.kampanakis-ml-kem-ikev2]
              Kampanakis, P. and G. Ravago, "Post-quantum Hybrid Key
              Exchange with ML-KEM in the Internet Key Exchange Protocol
              Version 2 (IKEv2)", Work in Progress, Internet-Draft,
              draft-kampanakis-ml-kem-ikev2-08, 18 September 2024,
              <https://datatracker.ietf.org/doc/html/draft-kampanakis-
              ml-kem-ikev2-08>.

   [NIST-PQ]  National Institute of Standards and Technology, "Post-
              Quantum Cryptography Project", 20 December 2016,
              <https://csrc.nist.gov/projects/post-quantum-
              cryptography>.

   [NIST.SP.800-57pt1r5]
              Barker, E. and NIST, "Recommendation for key
              management:part 1 - general", NIST Special Publications
              (General) 800-57pt1r5, DOI 10.6028/NIST.SP.800-57pt1r5,

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              May 2020,
              <https://nvlpubs.nist.gov/nistpubs/SpecialPublications/
              NIST.SP.800-57pt1r5.pdf>.

   [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/rfc/rfc4086>.

   [RFC5911]  Hoffman, P. and J. Schaad, "New ASN.1 Modules for
              Cryptographic Message Syntax (CMS) and S/MIME", RFC 5911,
              DOI 10.17487/RFC5911, June 2010,
              <https://www.rfc-editor.org/rfc/rfc5911>.

Appendix A.  ASN.1 Module

   RFC EDITOR: Please replace TBD2 with the value assigned by IANA
   during the publication of [I-D.ietf-lamps-kyber-certificates].

   <CODE BEGINS>
   CMS-ML-KEM-2024
   { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
     pkcs-9(9) smime(16) modules(0) id-mod-cms-ml-kem-2024(TBD1) }

   DEFINITIONS IMPLICIT TAGS ::= BEGIN

   EXPORTS ALL;

   IMPORTS
     SMIME-CAPS
       FROM AlgorithmInformation-2009  -- [RFC5911]
         { iso(1) identified-organization(3) dod(6) internet(1)
           security(5) mechanisms(5) pkix(7) id-mod(0)
           id-mod-algorithmInformation-02(58) }

     KEM-ALGORITHM
       FROM KEMAlgorithmInformation-2023  -- [RFC9629]
          { iso(1) identified-organization(3) dod(6) internet(1)
            security(5) mechanisms(5) pkix(7) id-mod(0)
            id-mod-kemAlgorithmInformation-2023(109) }

     kda-hkdf-with-sha256
       FROM HKDF-OID-2019  -- [RFC8619]
          { iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1)
            pkcs-9(9) smime(16) modules(0) id-mod-hkdf-oid-2019(68) }

     kwa-aes128-wrap, kwa-aes256-wrap
       FROM CMSAesRsaesOaep-2009

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          { iso(1) member-body(2) us(840) rsadsi(113549)
          pkcs(1) pkcs-9(9) smime(16) modules(0)
          id-mod-cms-aes-02(38) }

     id-alg-ml-kem-512, id-alg-ml-kem-768, id-alg-ml-kem-1024,
     pk-ml-kem-512, pk-ml-kem-768, pk-ml-kem-1024
       FROM X509-ML-KEM-2024
          { iso(1) identified-organization(3) dod(6)
            internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
            id-mod-x509-ml-kem-2024(TBD2) };

   --
   -- ML-KEM Key Encapsulation Mechanism Algorithms
   --

   kema-ml-kem-512 KEM-ALGORITHM ::= {
      IDENTIFIER id-alg-ml-kem-512
      PARAMS ARE absent
      PUBLIC-KEYS { pk-ml-kem-512 }
      UKM ARE optional
      SMIME-CAPS { IDENTIFIED BY id-alg-ml-kem-512 } }

   kema-ml-kem-768 KEM-ALGORITHM ::= {
      IDENTIFIER id-alg-ml-kem-768
      PARAMS ARE absent
      PUBLIC-KEYS { pk-ml-kem-768 }
      UKM ARE optional
      SMIME-CAPS { IDENTIFIED BY id-alg-ml-kem-768 } }

   kema-ml-kem-1024 KEM-ALGORITHM ::= {
      IDENTIFIER id-alg-ml-kem-1024
      PARAMS ARE absent
      PUBLIC-KEYS { pk-ml-kem-1024 }
      UKM ARE optional
      SMIME-CAPS { IDENTIFIED BY id-alg-ml-kem-1024 } }

   -- Updates for the SMIME-CAPS Set from RFC 5911

   SMimeCapsSet SMIME-CAPS ::=
      { kema-ml-kem-512.&smimeCaps |
        kema-ml-kem-768.&smimeCaps |
        kema-ml-kem-1024.&smimeCaps |
        kda-hkdf-with-sha256.&smimeCaps |
        kwa-aes128-wrap.&smimeCaps |
        kwa-aes256-wrap.&smimeCaps,
        ... }

   END

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   <CODE ENDS>

Appendix B.  ML-KEM CMS Enveloped-Data Example

   This example shows the establishment of an AES-128 content-encryption
   key using:

   *  ML-DSA-512 and HKDF with SHA-256;

   *  KEMRecipientInfo key derivation using HKDF with SHA-256; and

   *  KEMRecipientInfo key wrap using AES-128-KEYWRAP.

   In real-world use, the originator would encrypt the content-
   encryption key in a manner that would allow decryption with their own
   private key as well as the recipient's private key.  This is omitted
   in an attempt to simplify the example.

B.1.  Originator CMS Processing

   Alice obtains Bob's ML-KEM-512 public key:

     -----BEGIN PUBLIC KEY-----
     MIIDMjALBglghkgBZQMEBAEDggMhACTnc6B5UOyymOxQLDt8PzI2vIHkccIGsy1b
     uI6EZ4UVHbHHpbRRv3mZwW7AEu+YEbpcB6kkZ28jUTHWFfYIIIeUbq6hMa/nRcLT
     UPYcjTwBK+dRU1UbmfTHCdtrF3U0hyB7tXsBo6tTeQWCpP7LBrYxmAFBhp2JuUx6
     MO+TpIWVHVzyzS2UE4MEBQ/HDGWyCgL6WRKGRdrEfBc2Wg7loCc7RDjoOqWGYPcV
     n2HCLPVhemLWAeCRE0wcLUPSvUzhKZsrRk4cfSi5eZB7Dze4olQ8NFGiJ8WMi+Y3
     xjiTW/w6X/Y7bC+zf8JLFcn7jOvQNM85PXp4j3KIiXSnCAv1OEUDZO5peP0QQUU1
     CxvQQjxCj+kGHZ/EaKeFy7QD0Crhl69xccB0dMzZMgQFmynLv5kZd0Z4SuSkANQ8
     ymtoLDvMqyHznseJS68ru+ZRn88KkVMosF4UkhKjphLXASHQU5RyquuBORUGLY/q
     DXQSyCJ8AHAlzCYwEUdpqGzsMo84bB72AyN5LNL3mxZaQnxAuREpQIO8w13IREfG
     HEPbHDJVZBXqCcD2wBWllJk4Fjn3b0uid62UfZLARoNCvakIkT+wUv68FS+WGVoY
     zbvYqqPSpJg5GRrTT8KUDwLscRkBVPIDctMWFD20yppmL9iLSwPkrz/1xhbgEqdA
     HGG2kt8XdkIRmEZ2IeLUJeiDPPGCi4zlywkbNpgIHajQriGcNQnoQWQZG3vWe0n2
     ZGuHoF/lPZ0awi6roL7ZOWaysXSBYRv5DiXTP3EFD2lQGDMDECjQPUw2yMXBDRFY
     pYPAeuEGfXMhl8EDgcuie/06oy45kOxxiud6r8q2b9hnH5YzGjJLYSygm9jAhQrQ
     a80GWUdVHvvElgZLs7uEFHhKtgcFbYmDH4GaiLVLMo70cSpDdDXmdVc0J9mEOsSk
     ac5ztj+mgj7qfCkib6QXeAMCmSnASKugi9iSAEEmXalmN5Jksh75YlozJM0xyDTZ
     k5SqKn5seA97Y+ExjOJXOEzcsXhHV9vc/9HTgFGXNv+Lbj8u+q4i4NDoWIntY5eM
     +u9k28Eo
     -----END PUBLIC KEY-----

   Bob's ML-KEM-512 public key has the following key identifier:

     5017165E720D05D70CFDA5F47B54BD5008C3ABE1

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   Alice generates a shared secret and ciphertext using Bob's ML-KEM-512
   public key, derives the key-encryption key from the shared secret and
   CMSORIforKEMOtherInfo using HKDF with SHA-256, randomly generates a
   128-bit content-encryption key, uses AES-128-KEYWRAP to encrypt the
   content-encryption key with the key-encryption key, encrypts the
   plaintext content with the content-encryption key and encodes the
   EnvelopedData (using KEMRecipientInfo) and ContentInfo, and then
   sends the result to Bob.

   The Base64-encoded result is:

     MIID4AYJKoZIhvcNAQcDoIID0TCCA80CAQMxggOIpIIDhAYLKoZIhvcNAQkQDQMw
     ggNzAgEAgBRQFxZecg0F1wz9pfR7VL1QCMOr4TALBglghkgBZQMEBAEEggMAqXwh
     xkJt/Vd+oSOSIDXM8851hXdyECMaHp2hnWGL2JohQ38wE82Yg4GC3YfU8F/kA6EZ
     yK5p96HnJsXRfg3dzxprhf7QX4/UNo6v7nwk1JEP5cCwmuMOnbZfeKPb1Mr4qilG
     hlwjpq/r6fR9rZmGOyBG0ZDAQVNlNzgPqnlgK1V/DGYf6KAfWscdjRGs8xHMeRJg
     7vLDSz9A/u1Cu2dZWIMKzwK5snTK2FbOAYerTfDDBnYNoQFpcgoWOFN45SYDTvgb
     2n9sUxWHovMRKlF6j6f9UVa0uqHYzoIXaLU3R9f0LxUVSV6bJ3hQp87t2l3E5ysd
     k3pmqsKkHhBWltJSJeRjjELSDUYs8AuW7D0TnLH0Jt/q0XG7zm1C2cWhJ5oTij10
     yr4qf38mwbG9R1dAbkrtchxl8Rl9v0OJZgfUHJLuSVMTYAb6n3Ltc4tN8qIia3cy
     Lg+wan2CjnXA3fKGDMMWhvaH0GRirItKumKBXg11MuG8PjLm/neUX2MIE+3hzDBB
     GBqSI586EZAx+WgWEhn7sLKlbm8wZtY5jfaqobusj3hN/RxCzFtplq6e3H7tEpFv
     mblF9lSPNpeA06Tj+PXZxXjgupj4gRp+fsjcVheG/syt5MuiFuTG7xdDtWyU7K3e
     8ZBo+zSUysipy4QEFlrBo+tMvhyDffyOd/qaaQnT0cv2ctEU6OeshZ1+J+ptDmx7
     6K3WH+k9etrcwUTmblJn8FDM3czM7fC+XScB5CrNyl9C+W1TN/NzMxaXRQcWuDyJ
     3jRWXmtJEGksg489cJAv1QbZXQmDlarrwq/01Tb7PWbE1QjfRQ627p3ZtAmK6zf7
     wZ8m8ZhoVMRA7qoEd3wfDxmdv4AgGvKILntG3WPgEYpF37qJbHbD6FQqhJXN2kx1
     FUDtsYCmiXB/3+MSz3HDbmXJvC7oxVmpM7YQHWYsrmRE1xDZcQl5IOUHo6yjjDvI
     iAsbmd7BCbanMK8Izysi1Whkw/hjQIuBfi6lH4ykkhN1d9U0Ebn3OZ625WmEMA0G
     CyqGSIb3DQEJEAMcAgEgMAsGCWCGSAFlAwQBLQQoxaMpy4QqMaoK3B0wFDbqmvAW
     Kuo1hZIymSqlgVuw9FRNxbWvSMp24TA8BgkqhkiG9w0BBwEwHQYJYIZIAWUDBAEq
     BBB7U/4MxliKkV8ho6ZJIm9UgBDzlQzo0SLI9+VS4VoV1mvr

   This result decodes to:

       0 992: SEQUENCE {
       4   9:   OBJECT IDENTIFIER envelopedData (1 2 840 113549 1 7 3)
     15 977:   [0] {
     19 973:     SEQUENCE {
     23   1:       INTEGER 3
     26 904:       SET {
     30 900:         [4] {
     34  11:           OBJECT IDENTIFIER '1 2 840 113549 1 9 16 13 3'
     47 883:           SEQUENCE {
     51   1:             INTEGER 0
     54  20:             [0]
           :         50 17 16 5E 72 0D 05 D7 0C FD A5 F4 7B 54 BD 50
           :         08 C3 AB E1

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     76  11:             SEQUENCE {
     78   9:               OBJECT IDENTIFIER '2 16 840 1 101 3 4 4 1'
           :               }
     89 768:             OCTET STRING
           :         A9 7C 21 C6 42 6D FD 57 7E A1 23 92 20 35 CC F3
           :         CE 75 85 77 72 10 23 1A 1E 9D A1 9D 61 8B D8 9A
           :         21 43 7F 30 13 CD 98 83 81 82 DD 87 D4 F0 5F E4
           :         03 A1 19 C8 AE 69 F7 A1 E7 26 C5 D1 7E 0D DD CF
           :         1A 6B 85 FE D0 5F 8F D4 36 8E AF EE 7C 24 D4 91
           :         0F E5 C0 B0 9A E3 0E 9D B6 5F 78 A3 DB D4 CA F8
           :         AA 29 46 86 5C 23 A6 AF EB E9 F4 7D AD 99 86 3B
           :         20 46 D1 90 C0 41 53 65 37 38 0F AA 79 60 2B 55
           :         7F 0C 66 1F E8 A0 1F 5A C7 1D 8D 11 AC F3 11 CC
           :         79 12 60 EE F2 C3 4B 3F 40 FE ED 42 BB 67 59 58
           :         83 0A CF 02 B9 B2 74 CA D8 56 CE 01 87 AB 4D F0
           :         C3 06 76 0D A1 01 69 72 0A 16 38 53 78 E5 26 03
           :         4E F8 1B DA 7F 6C 53 15 87 A2 F3 11 2A 51 7A 8F
           :         A7 FD 51 56 B4 BA A1 D8 CE 82 17 68 B5 37 47 D7
           :         F4 2F 15 15 49 5E 9B 27 78 50 A7 CE ED DA 5D C4
           :         E7 2B 1D 93 7A 66 AA C2 A4 1E 10 56 96 D2 52 25
           :         E4 63 8C 42 D2 0D 46 2C F0 0B 96 EC 3D 13 9C B1
           :         F4 26 DF EA D1 71 BB CE 6D 42 D9 C5 A1 27 9A 13
           :         8A 3D 74 CA BE 2A 7F 7F 26 C1 B1 BD 47 57 40 6E
           :         4A ED 72 1C 65 F1 19 7D BF 43 89 66 07 D4 1C 92
           :         EE 49 53 13 60 06 FA 9F 72 ED 73 8B 4D F2 A2 22
           :         6B 77 32 2E 0F B0 6A 7D 82 8E 75 C0 DD F2 86 0C
           :         C3 16 86 F6 87 D0 64 62 AC 8B 4A BA 62 81 5E 0D
           :         75 32 E1 BC 3E 32 E6 FE 77 94 5F 63 08 13 ED E1
           :         CC 30 41 18 1A 92 23 9F 3A 11 90 31 F9 68 16 12
           :         19 FB B0 B2 A5 6E 6F 30 66 D6 39 8D F6 AA A1 BB
           :         AC 8F 78 4D FD 1C 42 CC 5B 69 96 AE 9E DC 7E ED
           :         12 91 6F 99 B9 45 F6 54 8F 36 97 80 D3 A4 E3 F8
           :         F5 D9 C5 78 E0 BA 98 F8 81 1A 7E 7E C8 DC 56 17
           :         86 FE CC AD E4 CB A2 16 E4 C6 EF 17 43 B5 6C 94
           :         EC AD DE F1 90 68 FB 34 94 CA C8 A9 CB 84 04 16
           :         5A C1 A3 EB 4C BE 1C 83 7D FC 8E 77 FA 9A 69 09
           :         D3 D1 CB F6 72 D1 14 E8 E7 AC 85 9D 7E 27 EA 6D
           :         0E 6C 7B E8 AD D6 1F E9 3D 7A DA DC C1 44 E6 6E
           :         52 67 F0 50 CC DD CC CC ED F0 BE 5D 27 01 E4 2A
           :         CD CA 5F 42 F9 6D 53 37 F3 73 33 16 97 45 07 16
           :         B8 3C 89 DE 34 56 5E 6B 49 10 69 2C 83 8F 3D 70
           :         90 2F D5 06 D9 5D 09 83 95 AA EB C2 AF F4 D5 36
           :         FB 3D 66 C4 D5 08 DF 45 0E B6 EE 9D D9 B4 09 8A
           :         EB 37 FB C1 9F 26 F1 98 68 54 C4 40 EE AA 04 77
           :         7C 1F 0F 19 9D BF 80 20 1A F2 88 2E 7B 46 DD 63
           :         E0 11 8A 45 DF BA 89 6C 76 C3 E8 54 2A 84 95 CD
           :         DA 4C 75 15 40 ED B1 80 A6 89 70 7F DF E3 12 CF
           :         71 C3 6E 65 C9 BC 2E E8 C5 59 A9 33 B6 10 1D 66

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           :         2C AE 64 44 D7 10 D9 71 09 79 20 E5 07 A3 AC A3
           :         8C 3B C8 88 0B 1B 99 DE C1 09 B6 A7 30 AF 08 CF
           :         2B 22 D5 68 64 C3 F8 63 40 8B 81 7E 2E A5 1F 8C
           :         A4 92 13 75 77 D5 34 11 B9 F7 39 9E B6 E5 69 84
     861  13:             SEQUENCE {
     863  11:               OBJECT IDENTIFIER
           :                 hkdfWithSha256 (1 2 840 113549 1 9 16 3 28)
           :               }
     876   1:             INTEGER 32
     879  11:             SEQUENCE {
     881   9:               OBJECT IDENTIFIER
           :                 aes256-wrap (2 16 840 1 101 3 4 1 45)
           :               }
     892  40:             OCTET STRING
           :         C5 A3 29 CB 84 2A 31 AA 0A DC 1D 30 14 36 EA 9A
           :         F0 16 2A EA 35 85 92 32 99 2A A5 81 5B B0 F4 54
           :         4D C5 B5 AF 48 CA 76 E1
           :             }
           :           }
           :         }
     934  60:       SEQUENCE {
     936   9:         OBJECT IDENTIFIER data (1 2 840 113549 1 7 1)
     947  29:         SEQUENCE {
     949   9:           OBJECT IDENTIFIER
           :             aes256-CBC (2 16 840 1 101 3 4 1 42)
     960  16:           OCTET STRING
           :         7B 53 FE 0C C6 58 8A 91 5F 21 A3 A6 49 22 6F 54
           :           }
     978  16:         [0]
           :         F3 95 0C E8 D1 22 C8 F7 E5 52 E1 5A 15 D6 6B EB
           :         }
           :       }
           :     }
           :   }

B.2.  Recipient CMS Processing

   Bob's ML-KEM-512 private key:

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     -----BEGIN PRIVATE KEY-----
     MIIGdAIBADALBglghkgBZQMEBAEEggZgccN7jmIdwnCzfWgVxgIPofRkZ+qPP+Jn
     e7kd/wBvcwFsqygTliNHMixSTSc4OckHLmuehHZcpOc+mKNGyMu+flEy73GrpjrB
     L/Q/WaS7Vxe665MIbDKCqhJJS2AFguuYDBWGOxuCZYSQhawoAfR0OAkA5RoihgMH
     OKAx+6F0V8VJLFyj2yuVpNqOn2J3/bJ+DAMZv/ki2TcNoiEI/ZBfO0iEOKmso1tG
     p0A+96odcQOM0Bw2ATrJBpubaMFsK5y9Trgl6fJjwQI2eidnYcxC0ME6fVqNRWrK
     RDk3+jBiPkBzMOdJIsemNYeIwKu/ZpCbn8guTogI0tscIDiciXQwBbNp0HePdasB
     f4FklaESWfzO2XNyI8x/7nyBn2OJQrup6ec1BjKphuA5saBPnpW4D8UMJaVeCdq7
     7jVBdQwJDcUzWMGe0JpDGAJTqtONrPg0xyplcGQDoiGklDJhEuS5uDUgkaM27bJT
     FiDJxeGM9fZenJG129pCOwcTnud3yjeMsKmQ1joFjPuF4WxJsTE7BZWO9joX3oR+
     BVcrsua7ndarRDmY2LzIXWguTtulaEUkPre5l2dZpnFBv1sBEVASk+RBW8AxckcQ
     ZdIBX8QyRtgZbdVd6gy/nVhWnGcbFKEfEZY69ZlTZHG4SScdALmRfMdV2DB+i+XC
     GQZYVaeamzUa5EFqtGwPi/tz+AeZEHESs/YMamZplGBr5eCTthsZi9NZs5is1dFE
     avMnXKbN7oWBTYyKeOFFDph+RSCNlnnH5hKtFHWsPMZqVVaD7TAT8mYuhOq1gGKE
     mHlPTJNlPom1LbRiUktp9yWB9fQ5c9C5IrLPnMCIhqdcZ/a0zlHELyZ3DPNeSepD
     lBSuUacgClq7FNuV2LMgsbFqiVLD1bSVYzRLAAOac/Z1EZDCyPu9vlglAH3G5SLF
     mypxVtST1XQ91gkurfwksUK13vSif6miRvV9gFwb+5d2kJIjdJAcKilDi5TL7+wQ
     YYN9qGkYCNuVYDMVRCI0VEIHjise4KZaJOdzoHlQ7LKY7FAsO3w/Mja8geRxwgaz
     LVu4joRnhRUdsceltFG/eZnBbsAS75gRulwHqSRnbyNRMdYV9gggh5RurqExr+dF
     wtNQ9hyNPAEr51FTVRuZ9McJ22sXdTSHIHu1ewGjq1N5BYKk/ssGtjGYAUGGnYm5
     THow75OkhZUdXPLNLZQTgwQFD8cMZbIKAvpZEoZF2sR8FzZaDuWgJztEOOg6pYZg
     9xWfYcIs9WF6YtYB4JETTBwtQ9K9TOEpmytGThx9KLl5kHsPN7iiVDw0UaInxYyL
     5jfGOJNb/Dpf9jtsL7N/wksVyfuM69A0zzk9eniPcoiJdKcIC/U4RQNk7ml4/RBB
     RTULG9BCPEKP6QYdn8Rop4XLtAPQKuGXr3FxwHR0zNkyBAWbKcu/mRl3RnhK5KQA
     1DzKa2gsO8yrIfOex4lLryu75lGfzwqRUyiwXhSSEqOmEtcBIdBTlHKq64E5FQYt
     j+oNdBLIInwAcCXMJjARR2mobOwyjzhsHvYDI3ks0vebFlpCfEC5ESlAg7zDXchE
     R8YcQ9scMlVkFeoJwPbAFaWUmTgWOfdvS6J3rZR9ksBGg0K9qQiRP7BS/rwVL5YZ
     WhjNu9iqo9KkmDkZGtNPwpQPAuxxGQFU8gNy0xYUPbTKmmYv2ItLA+SvP/XGFuAS
     p0AcYbaS3xd2QhGYRnYh4tQl6IM88YKLjOXLCRs2mAgdqNCuIZw1CehBZBkbe9Z7
     SfZka4egX+U9nRrCLqugvtk5ZrKxdIFhG/kOJdM/cQUPaVAYMwMQKNA9TDbIxcEN
     EVilg8B64QZ9cyGXwQOBy6J7/TqjLjmQ7HGK53qvyrZv2GcfljMaMkthLKCb2MCF
     CtBrzQZZR1Ue+8SWBkuzu4QUeEq2BwVtiYMfgZqItUsyjvRxKkN0NeZ1VzQn2YQ6
     xKRpznO2P6aCPup8KSJvpBd4AwKZKcBIq6CL2JIAQSZdqWY3kmSyHvliWjMkzTHI
     NNmTlKoqfmx4D3tj4TGM4lc4TNyxeEdX29z/0dOAUZc2/4tuPy76riLg0OhYie1j
     l4z672TbwSjZpZyRy7PJw/1ddylMqPKx+8P8zUDASMuBWGXxUXFXnH57d4puN9tR
     8okk0ej2GS/mY8DijpX4g0XMQ0RECPq4
     -----END PRIVATE KEY-----

   Bob decapsulates the ciphertext in the KEMRecipientInfo to get the
   ML-KEM-512 shared secret, derives the key-encryption key from the
   shared secret and CMSORIforKEMOtherInfo using HKDF with SHA-256, uses
   AES-128-KEYWRAP to decrypt the content-encryption key with the key-
   encryption key, and decrypts the encrypted contents with the content-
   encryption key, revealing the plaintext content:

     Hello, world!

Prat, et al.              Expires 18 April 2025                [Page 19]
Internet-Draft                ML-KEM in CMS                 October 2024

Authors' Addresses

   Julien Prat
   CryptoNext Security
   16, Boulevard Saint-Germain
   75005 Paris
   France
   Email: julien.prat@cryptonext-security.com

   Mike Ounsworth
   Entrust Limited
   2500 Solandt Road -- Suite 100
   Ottawa, Ontario  K2K 3G5
   Canada
   Email: mike.ounsworth@entrust.com

   Daniel Van Geest
   CryptoNext Security
   16, Boulevard Saint-Germain
   75005 Paris
   France
   Email: daniel.vangeest@cryptonext-security.com

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