Integral Cryptanalysis on reduced-round Safer++.
Gilles Piret, Jean-Jacques Quisquater · IACR Cryptology ePrint Archive · 2003
In this paper we describe an integral distinguisher over 2 rounds of Safer++. It allows a practical attack against 3 rounds of Safer++128, as well as attacks on 4 rounds of Safer++128 and Safer++256 (without the last key addition layer), under the chosen-plaintext hypothesis. These results achieve much lower complexity than the currently known best attacks on Safer++, namely weak-key linear cryptanalysis by Nakahara[9]. As a side result, we prove that the byte-branch number of the linear transform of Safer++ is 5. We also discuss a way for further research in order to extend integral cryptanalysis.