AES-GCM-SIV: Nonce Misuse-Resistant Authenticated Encryption
draft-irtf-cfrg-gcmsiv-05

Document Type Active Internet-Draft (cfrg RG)
Last updated 2017-05-23
Replaces draft-gueron-gcmsiv
Stream IRTF
Intended RFC status (None)
Formats plain text xml pdf html bibtex
Stream IRTF state (None)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
CFRG                                                           S. Gueron
Internet-Draft               University of Haifa and Amazon Web Services
Intended status: Informational                                A. Langley
Expires: November 22, 2017                                        Google
                                                              Y. Lindell
                                                     Bar Ilan University
                                                            May 21, 2017

      AES-GCM-SIV: Nonce Misuse-Resistant Authenticated Encryption
                       draft-irtf-cfrg-gcmsiv-05

Abstract

   This memo specifies two authenticated encryption algorithms that are
   nonce misuse-resistant - that is that they do not fail
   catastrophically if a nonce is repeated.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on November 22, 2017.

Copyright Notice

   Copyright (c) 2017 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
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of

Gueron, et al.          Expires November 22, 2017               [Page 1]
Internet-Draft                 aes-gcm-siv                      May 2017

   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  POLYVAL . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Encryption  . . . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Decryption  . . . . . . . . . . . . . . . . . . . . . . . . .   6
   6.  AEADs . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6
   7.  Field operation examples  . . . . . . . . . . . . . . . . . .   7
   8.  Worked example  . . . . . . . . . . . . . . . . . . . . . . .   7
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     12.1.  Normative References . . . . . . . . . . . . . . . . . .   9
     12.2.  Informative References . . . . . . . . . . . . . . . . .  10
   Appendix A.  The relationship between POLYVAL and GHASH . . . . .  10
   Appendix B.  Additional comparisons with AES-GCM  . . . . . . . .  12
   Appendix C.  Test vectors . . . . . . . . . . . . . . . . . . . .  12
     C.1.  AEAD_AES_128_GCM_SIV  . . . . . . . . . . . . . . . . . .  12
     C.2.  AEAD_AES_256_GCM_SIV  . . . . . . . . . . . . . . . . . .  19
     C.3.  Counter wrap tests  . . . . . . . . . . . . . . . . . . .  27
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  28

1.  Introduction

   The concept of "Authenticated encryption with additional data" (AEAD
   [RFC5116]) couples confidentiality and integrity in a single
   operation that is easier for practitioners to use correctly.  The
   most popular AEAD, AES-GCM [GCM], is seeing widespread use due to its
   attractive performance.

   However, most AEADs suffer catastrophic failures of confidentiality
   and/or integrity when two distinct messages are encrypted with the
   same nonce.  While the requirements for AEADs specify that the pair
   of (key, nonce) shall only ever be used once, and thus prohibit this,
   in practice this is a worry.

   Nonce misuse-resistant AEADs do not suffer from this problem.  For
   this class of AEADs, encrypting two messages with the same nonce only
   discloses whether the messages were equal or not.  This is the
   minimum amount of information that a deterministic algorithm can leak
Show full document text