Using Counter Modes with Encapsulating Security Payload (ESP) and Authentication Header (AH) to Protect Group Traffic
RFC 6054
Internet Engineering Task Force (IETF) D. McGrew
Request for Comments: 6054 B. Weis
Category: Standards Track Cisco Systems
ISSN: 2070-1721 November 2010
Using Counter Modes with Encapsulating Security Payload (ESP) and
Authentication Header (AH) to Protect Group Traffic
Abstract
Counter modes have been defined for block ciphers such as the
Advanced Encryption Standard (AES). Counter modes use a counter,
which is typically assumed to be incremented by a single sender.
This memo describes the use of counter modes when applied to the
Encapsulating Security Payload (ESP) and Authentication Header (AH)
in multiple-sender group applications.
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
http://www.rfc-editor.org/info/rfc6054.
Copyright Notice
Copyright (c) 2010 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
Provisions Relating to IETF Documents
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
McGrew & Weis Standards Track [Page 1]
RFC 6054 Group Counter Modes November 2010
Table of Contents
1. Introduction ....................................................2
1.1. Requirements Notation ......................................2
2. Problem Statement ...............................................2
3. IV Formation for Counter Modes with Group Keys ..................3
4. Group Key Management Conventions ................................4
5. Security Considerations .........................................5
6. Acknowledgements ................................................6
7. References ......................................................6
7.1. Normative References .......................................6
7.2. Informative References .....................................6
Appendix A. Rationale for the IV Formation for Counter Modes
with Group Keys ........................................9
Appendix B. Example ................................................9
1. Introduction
The IP Encapsulating Security Payload (ESP) specification [RFC4303]
and Authentication Header (AH) [RFC4302] are security protocols for
IPsec [RFC4301]. Several new AES encryption modes of operation have
been specified for ESP: Counter Mode (CTR) [RFC3686], Galois/Counter
Mode (GCM) [RFC4106], and Counter with Cipher Block Chaining-Message
Authentication Code (CBC-MAC) Mode (CCM) [RFC4309]; and one that has
been specified for both ESP and AH: the Galois Message Authentication
Code (GMAC) [RFC4543]. A Camellia counter mode [RFC5528] and a GOST
counter mode [RFC4357] have also been specified. These new modes
offer advantages over traditional modes of operation. However, they
all have restrictions on their use in situations in which multiple
senders are protecting traffic using the same key. This document
addresses this restriction and describes how these modes can be used
with group key management protocols such as the Group Domain of
Interpretation (GDOI) protocol [RFC3547] and the Group Secure
Association Key Management Protocol (GSAKMP) [RFC4535].
1.1. Requirements Notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. Problem Statement
The Counter Mode (CTR) of operation [FIPS.800-38A.2001] has become
important because of its performance and implementation advantages.
It is the basis for several modes of operation that combine
authentication with encryption, including CCM and GCM. All of the
counter-based modes require that, if a single key is shared by
McGrew & Weis Standards Track [Page 2]
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