Some Observations on SHAMATA

Improved Cryptanalysis of SHAMATA-BC

We state the design flaws of the 1-round block cipher SHAMATA-BC, designed by Fleishmann and Gorski by using the building blocks of SHAMATA hash function. We fix the flaws and then show that the amended version of SHAMATA-BC is much weaker. We believe that there is no connection between security level of SHAMATA as a hash function and that of SHAMATA-BC as a block cipher.

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 expan...

Cryptanalysis of the SHA-3 candidates EnRUPT and SHAMATA

In this talk, we review the successful cryptanalysis of two cryptographic hash functions, EnRUPT and SHAMATA. Both were submitted as candidates to the NIST SHA-3 competition.

Second Preimage Attack on SHAMATA-512

We present a second preimage attack on SHAMATA-512, which is a hash function of 512bit output and one of the first round candidates of the SHA-3 competition. The attack uses differential paths that hold with a probability one and a meet-in-the-middle approach to find second preimages. The time complexity is about 2 computation of the step function and the memory complexity is about 2 blocks of ...

Some observations on the feeding of the guinea pig