Practical Collisions for SHAMATA-256

In this paper, we present a collision attack on the SHA-3 submission SHAMATA. SHAMATA is a stream cipher-like hash function design with components of the AES, and it is one of the fastest submitted hash functions. In our attack, we show weaknesses in the message injection and state update of SHAMATA. It is possible to find certain message differences that do not get changed by the message expansion and non-linear part of the state update function. This allows us to find a differential path with a complexity of about 2 96 for SHAMATA-256 and about 2 110 for SHAMATA-512, using a linear low-weight codeword search. Using an efficient guess-and-determine technique we can significantly improve the complexity of this differential path for SHAMATA-256. With a complexity of about 2 40 we are even able to construct practical collisions for the full hash function SHAMATA-256. © 2009 Springer-Verlag Berlin Heidelberg.

ISBN:3642054439

Publication year:2009

BOF-keylabel:yes

IOF-keylabel:yes

Authors from:Higher Education

Accessibility:Open