RFC 3686 (rfc3686) - Page 1 of 19


Using Advanced Encryption Standard (AES) Counter Mode With IPsec Encapsulating Security Payload (ESP)



Alternative Format: Original Text Document



Network Working Group                                         R. Housley
Request for Comments: 3686                                Vigil Security
Category: Standards Track                                   January 2004


         Using Advanced Encryption Standard (AES) Counter Mode
            With IPsec Encapsulating Security Payload (ESP)

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2004).  All Rights Reserved.

Abstract

   This document describes the use of Advanced Encryption Standard (AES)
   Counter Mode, with an explicit initialization vector, as an IPsec
   Encapsulating Security Payload (ESP) confidentiality mechanism.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  2
       1.1.  Conventions Used In This Document. . . . . . . . . . . .  2
   2.  AES Block Cipher . . . . . . . . . . . . . . . . . . . . . . .  2
       2.1.  Counter Mode . . . . . . . . . . . . . . . . . . . . . .  2
       2.2.  Key Size and Rounds. . . . . . . . . . . . . . . . . . .  5
       2.3.  Block Size . . . . . . . . . . . . . . . . . . . . . . .  5
   3.  ESP Payload. . . . . . . . . . . . . . . . . . . . . . . . . .  5
       3.1.  Initialization Vector. . . . . . . . . . . . . . . . . .  6
       3.2.  Encrypted Payload. . . . . . . . . . . . . . . . . . . .  6
       3.3.  Authentication Data. . . . . . . . . . . . . . . . . . .  6
   4.  Counter Block Format . . . . . . . . . . . . . . . . . . . . .  7
   5.  IKE Conventions. . . . . . . . . . . . . . . . . . . . . . . .  8
       5.1.  Keying Material and Nonces . . . . . . . . . . . . . . .  8
       5.2.  Phase 1 Identifier . . . . . . . . . . . . . . . . . . .  9
       5.3.  Phase 2 Identifier . . . . . . . . . . . . . . . . . . .  9
       5.4.  Key Length Attribute . . . . . . . . . . . . . . . . . .  9
   6.  Test Vectors . . . . . . . . . . . . . . . . . . . . . . . . .  9
   7.  Security Considerations. . . . . . . . . . . . . . . . . . . . 12
   8.  Design Rationale . . . . . . . . . . . . . . . . . . . . . . . 14
   9.  IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 16



Housley                     Standards Track