Practical Collisions for EnRUPT

Abstract. The EnRUPT hash functions were proposed by O’Neil, Nohl and Henzen [5] as candidates for the SHA-3 competition, organised by NIST [4]. The proposal contains seven concrete hash functions, each hav-ing a different digest length. We present a practical collision attack on each of these seven EnRUPT variants. The time complexity of our attack varies from 236 to 240 round computations, depending on the EnRUPT variant, and the memory re-quirements are negligible. We demonstrate that our attack is practical by giving an actual collision example for EnRUPT-256. Key words: EnRUPT, SHA-3 candidate, hash function, collision attack.