The BLAKE2 Cryptographic Hash and Message Authentication Code (MAC)
RFC 7693
| Document | Type |
RFC - Informational
(November 2015; No errata)
Was draft-saarinen-blake2 (individual)
|
|
|---|---|---|---|
| Authors | Markku-Juhani Saarinen , Jean-Philippe Aumasson | ||
| Last updated | 2015-11-03 | ||
| Stream | ISE | ||
| Formats | plain text html pdf htmlized bibtex | ||
| IETF conflict review | conflict-review-saarinen-blake2 | ||
| Stream | ISE state | Published RFC | |
| Consensus Boilerplate | Unknown | ||
| Document shepherd | Adrian Farrel | ||
| Shepherd write-up | Show (last changed 2015-06-18) | ||
| IESG | IESG state | RFC 7693 (Informational) | |
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | No IANA Actions | ||
Independent Submission M-J. Saarinen, Ed.
Request for Comments: 7693 Queen's University Belfast
Category: Informational J-P. Aumasson
ISSN: 2070-1721 Kudelski Security
November 2015
The BLAKE2 Cryptographic Hash and Message Authentication Code (MAC)
Abstract
This document describes the cryptographic hash function BLAKE2 and
makes the algorithm specification and C source code conveniently
available to the Internet community. BLAKE2 comes in two main
flavors: BLAKE2b is optimized for 64-bit platforms and BLAKE2s for
smaller architectures. BLAKE2 can be directly keyed, making it
functionally equivalent to a Message Authentication Code (MAC).
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This is a contribution to the RFC Series, independently of any other
RFC stream. The RFC Editor has chosen to publish this document at
its discretion and makes no statement about its value for
implementation or deployment. Documents approved for publication by
the RFC Editor are not a candidate for any level of Internet
Standard; see 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/rfc7693.
Copyright Notice
Copyright (c) 2015 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.
Saarinen & Aumasson Informational [Page 1]
RFC 7693 BLAKE2 Crypto Hash and MAC November 2015
Table of Contents
1. Introduction and Terminology . . . . . . . . . . . . . . . . 3
2. Conventions, Variables, and Constants . . . . . . . . . . . . 4
2.1. Parameters . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Other Constants and Variables . . . . . . . . . . . . . . 4
2.3. Arithmetic Notation . . . . . . . . . . . . . . . . . . . 4
2.4. Little-Endian Interpretation of Words as Bytes . . . . . 5
2.5. Parameter Block . . . . . . . . . . . . . . . . . . . . . 5
2.6. Initialization Vector . . . . . . . . . . . . . . . . . . 6
2.7. Message Schedule SIGMA . . . . . . . . . . . . . . . . . 6
3. BLAKE2 Processing . . . . . . . . . . . . . . . . . . . . . . 7
3.1. Mixing Function G . . . . . . . . . . . . . . . . . . . . 7
3.2. Compression Function F . . . . . . . . . . . . . . . . . 8
3.3. Padding Data and Computing a BLAKE2 Digest . . . . . . . 9
4. Standard Parameter Sets and Algorithm Identifiers . . . . . . 10
5. Security Considerations . . . . . . . . . . . . . . . . . . . 11
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Normative References . . . . . . . . . . . . . . . . . . 11
6.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Example of BLAKE2b Computation . . . . . . . . . . . 13
Appendix B. Example of BLAKE2s Computation . . . . . . . . . . . 15
Appendix C. BLAKE2b Implementation C Source . . . . . . . . . . 16
C.1. blake2b.h . . . . . . . . . . . . . . . . . . . . . . . . 16
C.2. blake2b.c . . . . . . . . . . . . . . . . . . . . . . . . 17
Appendix D. BLAKE2s Implementation C Source . . . . . . . . . . 21
D.1. blake2s.h . . . . . . . . . . . . . . . . . . . . . . . . 21
D.2. blake2s.c . . . . . . . . . . . . . . . . . . . . . . . . 22
Appendix E. BLAKE2b and BLAKE2s Self-Test Module C Source . . . 26
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30
Saarinen & Aumasson Informational [Page 2]
RFC 7693 BLAKE2 Crypto Hash and MAC November 2015
1. Introduction and Terminology
The BLAKE2 cryptographic hash function [BLAKE2] was designed by Jean-
Philippe Aumasson, Samuel Neves, Zooko Wilcox-O'Hearn, and Christian
Winnerlein.
BLAKE2 comes in two basic flavors:
o BLAKE2b (or just BLAKE2) is optimized for 64-bit platforms and
produces digests of any size between 1 and 64 bytes.
o BLAKE2s is optimized for 8- to 32-bit platforms and produces
digests of any size between 1 and 32 bytes.
Both BLAKE2b and BLAKE2s are believed to be highly secure and perform
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