Fast Software Encryption

Volume 5086 of the series Lecture Notes in Computer Science pp 16-35

Collisions on SHA-0 in One Hour

  • Stéphane ManuelAffiliated withINRIA
  • , Thomas PeyrinAffiliated withOrange LabsAISTUniversité de Versailles Saint-Quentin-en-Yvelines


At Crypto 2007, Joux and Peyrin showed that the boomerang attack, a classical tool in block cipher cryptanalysis, can also be very useful when analyzing hash functions. They applied their new theoretical results to SHA and provided new improvements for the cryptanalysis of this algorithm. In this paper, we concentrate on the case of SHA-0. First, we show that the previous perturbation vectors used in all known attacks are not optimal and we provide a new 2-block one. The problem of the possible existence of message modifications for this vector is tackled by the utilization of auxiliary differentials from the boomerang attack, relatively simple to use. Finally, we are able to produce the best collision attack against SHA-0 so far, with a measured complexity of 233,6 hash function calls. Finding one collision for SHA-0 takes us approximatively one hour of computation on an average PC.


hash functions SHA-0 boomerang attack