Internet Engineering Task Force (IETF) S. Turner
Request for Comments: 6161 IECA
Updates: 6033 April 2011
Category: Standards Track
Elliptic Curve Algorithms for Cryptographic Message Syntax (CMS)
Encrypted Key Package Content Type
This document describes the conventions for using several Elliptic
Curve cryptographic algorithms with the Cryptographic Message Syntax
(CMS) encrypted key package content type. Specifically, it includes
conventions necessary to implement Elliptic Curve Diffie-Hellman
(ECDH) with EnvelopedData and Elliptic Curve Digital Signature
Algorithm (ECDSA) with SignedData. This document extends RFC 6033.
Status of This Memo
This is an Internet Standards Track document.
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). Further information on
Internet Standards is available in 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
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Turner Standards Track [Page 1]RFC 6161 EC Algorithms for CMS Encrypted Key Packages April 20111. Introduction
This document describes the conventions for using Elliptic Curve
cryptographic algorithms with the Cryptographic Message Syntax (CMS)
encrypted key package content type [RFC6032]. Specifically, it
includes conventions necessary to implement the following CMS content
types: EnvelopedData [RFC5652] and SignedData [RFC5652]. This
document amends [RFC6033]. Familiarity with [RFC6033] and [RFC5753]
This document does not define any new algorithms; instead, it refers
to previously defined algorithms.
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
When key agreement is used, standard (as opposed to cofactor) ECDH
[RFC6090][RFC5753] MAY be supported.
If an implementation encapsulates EncryptedKeyPackage with SignedData
[RFC5652], then it MAY support the signature scheme ECDSA
4. Public Key Sizes
The easiest way to implement SignedData and EnvelopedData is with
public key certificates [RFC5280][RFC5480]. If an implementation
supports ECDSA or ECDH, then it MUST support keys on the P-256 curve.
5. Security Considerations
The security considerations from [RFC5280], [RFC5480], [RFC5652],
[RFC5753], [RFC6033], and [RFC6090] apply.
6. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
Turner Standards Track [Page 2]RFC 6161 EC Algorithms for CMS Encrypted Key Packages April 2011
[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, May 2008.
[RFC5480] Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk,
"Elliptic Curve Cryptography Subject Public Key
Information", RFC 5480, March 2009.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,