Rotational Cryptanalysis of Round-Reduced Keccak

Abstract

In this paper we attack round-reduced Keccak hash function with a technique called rotational cryptanalysis. We focus on Keccak variants proposed as SHA-3 candidates in the NIST’s contest for a new standard of cryptographic hash function. Our main result is a preimage attack on 4-round Keccak and a 5-round distinguisher on Keccak-\(f\)[1600] permutation — the main building block of Keccak hash function.