Paper 2010/057

Message Recovery and Pseudo-Preimage Attacks on the Compression Function of Hamsi-256

Cagdas Calik and Meltem Sonmez Turan


Hamsi is one of the second round candidates of the SHA-3 competition. In this study, we present non-random differential properties for the compression function of the hash function Hamsi-256. Based on these properties, we first demonstrate a distinguishing attack that requires a few evaluations of the compression function and extend the distinguisher to 5 rounds with complexity $2^{83}$. Then, we present a message recovery attack with complexity of $2^{10.48}$ compression function evaluations. Also, we present a pseudo-preimage attack for the compression function with complexity $2^{254.25}$. The pseudo-preimage attack on the compression function is easily converted to a pseudo second preimage attack on Hamsi-256 hash function with the same complexity.

Available format(s)
Secret-key cryptography
Publication info
Published elsewhere. Unknown where it was published
Hash functionsSHA-3 competitioncryptanalysispreimage attacks
Contact author(s)
meltemsturan @ gmail com
2010-02-15: revised
2010-02-08: received
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Creative Commons Attribution


      author = {Cagdas Calik and Meltem Sonmez Turan},
      title = {Message Recovery and Pseudo-Preimage Attacks on the Compression Function of Hamsi-256},
      howpublished = {Cryptology ePrint Archive, Paper 2010/057},
      year = {2010},
      note = {\url{}},
      url = {}
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