A New Technique for Multidimensional Linear Cryptanalysis with Applications on Reduced Round Serpent

Abstract. In this paper, we present a new technique for Matsui's algorithm 2 using multidimensional linear approximation. We show that the data complexity of the attack can be reduced significantly by our method even when the linear hull effect is present. We apply our method to the key recovery attack on 5-round Serpent and demonstrate that our attack is superior to previous attacks. We present evidence that it is theoretically possible to reduce the data complexity of the linear attack against 10 round Serpent by factor of 220 when multiple approximations are used.

• Type: Conference
• Year: 2008
• Where: ICISC
• Authors: Joo Yeon Cho, Miia Hermelin, Kaisa Nyberg
• Keywords: Cryptology, Data Complexity, ICISC 2008, Linear Hull Effect, Multidimensional Linear Approximation