BLAKE

1 The algorithm

Author(s): Jean-Philippe Aumasson, Luca Henzen, Willi Meier, Raphael C.-W. Phan
Website: http://131002.net/blake/
NIST submission package:
- round 1/2: BLAKE_Round2.zip (old versions: BLAKE.zip, BLAKEUpdate.zip)

Jean-Philippe Aumasson, Luca Henzen, Willi Meier, Raphael C.-W. Phan - SHA-3 proposal BLAKE

,2008

http://131002.net/blake/blake.pdf
Bibtex

Author : Jean-Philippe Aumasson, Luca Henzen, Willi Meier, Raphael C.-W. Phan
Title : SHA-3 proposal BLAKE
In : -
Address :
Date : 2008

2 Cryptanalysis

We distinguish between two cases: results on the complete hash function, and results on underlying building blocks.

A description of the tables is given here.

Recommended security parameter: 10 rounds (n=224,256); 14 rounds (n=384,512)

2.1 Hash function

Here we list results on the hash function according to the NIST requirements. The only allowed modification is to change the security parameter.

Type of Analysis	Hash Size (n)	Parameters	Compression Function Calls	Memory Requirements	Reference
preimage	224,256	2.5 rounds	2^n-15	-	Ji,Liangyu
preimage	384	2.5 rounds	2³⁵⁵	-	Ji,Liangyu
preimage	512	2.5 rounds	2⁴⁸¹	-	Ji,Liangyu

2.2 Building blocks

Here we list results on underlying building blocks, and the hash function modified by other means than the security parameter.

Note that these results assume more direct control or access over some internal variables (aka. free-start, pseudo, compression function, block cipher, or permutation attacks).

Type of Analysis	Hash Function Part	Hash Size (n)	Parameters/Variants	Compression Function Calls	Memory Requirements	Reference
impossible differential	permutation	224,256	5 rounds	-	-	Aumasson,Guo,Knellwolf,Matusiewicz,Meier
impossible differential	permutation	384,512	6 rounds	-	-	Aumasson,Guo,Knellwolf,Matusiewicz,Meier
near-collision	compression function	256	4 rounds (nb. 3-6)	2⁵⁶	-	Guo,Matusiewicz
free-start collision	hash	224,256	2.5 rounds	2^n/2-16	-	Ji,Liangyu
free-start collision	hash	384,512	2.5 rounds	2^n/2-32	-	Ji,Liangyu

Jean-Philippe Aumasson, Jian Guo, Simon Knellwolf, Krystian Matusiewicz, Willi Meier - Differential and invertibility properties of BLAKE (full version)

,2010

http://eprint.iacr.org/2010/043.pdf
Bibtex

Author : Jean-Philippe Aumasson, Jian Guo, Simon Knellwolf, Krystian Matusiewicz, Willi Meier
Title : Differential and invertibility properties of BLAKE (full version)
In : -
Address :
Date : 2010

Jian Guo, Krystian Matusiewicz - Round-Reduced Near-Collisions of BLAKE-32

,2009

http://www.jguo.org/docs/blake-col.pdf
Bibtex

Author : Jian Guo, Krystian Matusiewicz
Title : Round-Reduced Near-Collisions of BLAKE-32
In : -
Address :
Date : 2009

Li Ji, Xu Liangyu - Attacks on Round-Reduced BLAKE

,2009

http://eprint.iacr.org/2009/238.pdf
Bibtex

Author : Li Ji, Xu Liangyu
Title : Attacks on Round-Reduced BLAKE
In : -
Address :
Date : 2009