Use of Static-Static Elliptic Curve Diffie-Hellman Key Agreement in Cryptographic Message Syntax
RFC 6278

Internet Engineering Task Force (IETF)                         J. Herzog
Request for Comments: 6278                                     R. Khazan
Category: Informational                           MIT Lincoln Laboratory
ISSN: 2070-1721                                                June 2011

  Use of Static-Static Elliptic Curve Diffie-Hellman Key Agreement in
                      Cryptographic Message Syntax

Abstract

   This document describes how to use the 'static-static Elliptic Curve
   Diffie-Hellman key-agreement scheme (i.e., Elliptic Curve Diffie-
   Hellman where both participants use static Diffie-Hellman values)
   with the Cryptographic Message Syntax.  In this form of key
   agreement, the Diffie-Hellman values of both the sender and receiver
   are long-term values contained in certificates.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6278.

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RFC 6278                Static-Static ECDH in CMS              June 2011

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................2
      1.1. Requirements Terminology ...................................5
   2. EnvelopedData Using Static-Static ECDH ..........................5
      2.1. Fields of the KeyAgreeRecipientInfo ........................5
      2.2. Actions of the Sending Agent ...............................6
      2.3. Actions of the Receiving Agent .............................7
   3. AuthenticatedData Using Static-Static ECDH ......................8
      3.1. Fields of the KeyAgreeRecipientInfo ........................8
      3.2. Actions of the Sending Agent ...............................8
      3.3. Actions of the Receiving Agent .............................9
   4. AuthEnvelopedData Using Static-Static ECDH ......................9
      4.1. Fields of the KeyAgreeRecipientInfo ........................9
      4.2. Actions of the Sending Agent ...............................9
      4.3. Actions of the Receiving Agent .............................9
   5. Comparison to RFC 5753 ..........................................9
   6. Requirements and Recommendations ...............................10
   7. Security Considerations ........................................12
   8. Acknowledgements ...............................................14
   9. References .....................................................14
      9.1. Normative References ......................................14
      9.2. Informative References ....................................15

1.  Introduction

   This document describes how to use the static-static Elliptic Curve
   Diffie-Hellman key-agreement scheme (i.e., Elliptic Curve Diffie-
   Hellman [RFC6090] where both participants use static Diffie-Hellman
   values) in the Cryptographic Message Syntax (CMS) [RFC5652].  The CMS
   is a standard notation and representation for cryptographic messages.
   The CMS uses ASN.1 notation [X.680] [X.681] [X.682] [X.683] to define

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RFC 6278                Static-Static ECDH in CMS              June 2011

   a number of structures that carry both cryptographically protected
   information and key-management information regarding the keys used.
   Of particular interest here are three structures:

   o  EnvelopedData, which holds encrypted (but not necessarily