Provided by: University of Haifa
Date Added: Nov 2011
The Keccak hash function is one of the five finalists in NIST's SHA-3 competition, and so far it showed remarkable resistance against practical collision finding attacks: after several years of cryptanalysis and a lot of effort, the largest number of Keccak rounds for which actual collisions were found was only 2. In this paper, the authors develop improved collision finding techniques which enable one to double this number. More precisely, they can now find within a few minutes on a single PC actual collisions in standard Keccak-224 and Keccak-256, where the only modification is to reduce their number of rounds to 4.