AES-GCM-SIV: Nonce Misuse-Resistant Authenticated Encryption
RFC 8452
Internet Research Task Force (IRTF) S. Gueron
Request for Comments: 8452 University of Haifa and Amazon
Category: Informational A. Langley
ISSN: 2070-1721 Google LLC
Y. Lindell
Bar-Ilan University and Unbound Tech
April 2019
AES-GCM-SIV: Nonce Misuse-Resistant Authenticated Encryption
Abstract
This memo specifies two authenticated encryption algorithms that are
nonce misuse resistant -- that is, they do not fail catastrophically
if a nonce is repeated.
This document is the product of the Crypto Forum Research Group.
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 Research Task Force
(IRTF). The IRTF publishes the results of Internet-related research
and development activities. These results might not be suitable for
deployment. This RFC represents the consensus of the Crypto Forum
Research Group of the Internet Research Task Force (IRTF). Documents
approved for publication by the IRSG are not candidates for any level
of Internet Standard; see Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8452.
Copyright Notice
Copyright (c) 2019 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
(https://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.
Gueron, et al. Informational [Page 1]
RFC 8452 AES-GCM-SIV April 2019
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. POLYVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Encryption . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Decryption . . . . . . . . . . . . . . . . . . . . . . . . . 7
6. AEADs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Field Operation Examples . . . . . . . . . . . . . . . . . . 10
8. Worked Example . . . . . . . . . . . . . . . . . . . . . . . 10
9. Security Considerations . . . . . . . . . . . . . . . . . . . 11
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.1. Normative References . . . . . . . . . . . . . . . . . . 14
11.2. Informative References . . . . . . . . . . . . . . . . . 15
Appendix A. The Relationship between POLYVAL and GHASH . . . . . 17
Appendix B. Additional Comparisons with AES-GCM . . . . . . . . 19
Appendix C. Test Vectors . . . . . . . . . . . . . . . . . . . . 20
C.1. AEAD_AES_128_GCM_SIV . . . . . . . . . . . . . . . . . . 20
C.2. AEAD_AES_256_GCM_SIV . . . . . . . . . . . . . . . . . . 30
C.3. Counter Wrap Tests . . . . . . . . . . . . . . . . . . . 41
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 42
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 42
1. Introduction
The concept of Authenticated Encryption with Additional Data (AEAD)
[RFC5116] couples confidentiality and integrity in a single
operation, avoiding the risks of the previously common practice of
using ad hoc constructions of block-cipher and hash primitives. The
most popular AEAD, AES-GCM [GCM], is seeing widespread use due to its
attractive performance.
However, some AEADs (including AES-GCM) suffer catastrophic failures
of confidentiality and/or integrity when two distinct messages are
encrypted with the same key and nonce. While the requirements for
AEADs specify that the pair of (key, nonce) shall only ever be used
once, and thus prohibit this, this is a worry in practice.
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
in this situation.
This memo specifies two nonce misuse-resistant AEADs:
AEAD_AES_128_GCM_SIV and AEAD_AES_256_GCM_SIV. These AEADs are
designed to be able to take advantage of existing hardware support
Show full document text