Collision Attack on 5 Rounds of Groestl

© International Association for Cryptologic Research 2015. In this article, we describe a novel collision attack for up to 5 rounds of the Grøstl hash function. This significantly improves upon the best previously published results on 3 rounds. By using a new type of differential trail spanning over more than one message block we are able to construct collisions for Grøstl-256 on 4 and 5 rounds with complexity of 267 and 2120, respectively. Both attacks need 264 memory. Due to the generic nature of our attack we can even construct meaningful collisions in the chosen-prefix setting with the same attack complexity.

ISBN:978-3-662-46705-3

Publication year:2014

BOF-keylabel:yes

IOF-keylabel:yes

Authors from:Government, Higher Education