BLAKE (hash function)

BLAKE is a cryptographic hash function, which in 2008 by Jean -Philippe Aumasson, Luca Henzen, Willi Meier, and Raphael C.-W. Phan was developed. BLAKE was one of the finalists in the SHA -3 competition of NIST.

Structure

For the SHA -3 method supports BLAKE hash values ​​of 224, 256, 384 and 512 bits; usually, however, only the lengths of 256 and 512 bits, which are denoted by 256 and BLAKE BLAKE 512. The algorithm operates on 256 BLAKE 32- bit words, BLAKE 512 operates on 64- bit words. The compression function corresponds to the system launched in 2007 HAIFA structure, the algorithm is based on the stream cipher ChaCha, a further development of Salsa20. During the SHA -3 competition, the number of rounds for BLAKE -256 was increased from 10 to 14 and BLAKE -512 from 14 to 16 rounds.

Properties

BLAKE had together with Skein in the SHA -3 method is the best software performance and was faster than SHA -2 in most cases. However, the algorithm showed especially compared to the winner Keccak on a much worse hardware performance.

Security

In the SHA -3 method, a high margin of safety was adopted for BLAKE, was also the algorithm as well understood and analyzed intensively. Published in 2011, Alex Biryukov, Ivica Nikolic and Arnab Roy an attack on 8 rounds of BLAKE -256, but dar. with a complexity of 2232nd The attack was considered in the selection process and provides up to as of December 2013, the best cryptanalysis

BLAKE2

Published in 2012, Jean- Philippe Aumasson, Samuel Neves, Zooko Wilcox - O'Hearn and Christian Winnerlein BLAKE2 as an evolution of BLAKE. BLAKE2 is primarily aimed at further improving the performance with the same safety features and is on 64- bit platforms be as SHA -1, MD5 and MD4 faster. In a first analysis, the authors assume slightly lower safety properties over BLAKE.