Cryptanalysis of MV3 stream cipher

Abstract

MV3 is a word-based stream cipher, which was presented at the CT-RSA 2007 and SASC 2007 Conferences. Although it supports various key sizes of up to 8192 bits, the security claim of MV3 is that no attack faster than the exhaustive key search can be mounted for keys of length up to 256 bits. This paper provides a distinguishing attack on the MV3 stream cipher. We will show that the key stream generated in MV3 is distinguishable from random sequences after observing approximately 262.93 bits. That is, in the MV3 cipher with keys of length larger than 63 bits, it is possible to design a key search attack faster than the exhaustive search. © 2008 Springer Berlin Heidelberg.