Security Analysis of the Full-Round CHESS-64 Cipher Suitable for Pervasive Computing Environments

Changhoon Lee (Hanshin University, Korea)

Jongsung Kim (Korea University, Korea)

Seokhie Hong (Korea University, Korea)

Yang-Sun Lee (FUMATE Co., Korea)

Abstract: Wireless networks, telecommunications, and information technologies connected de-vices in pervasive computing environments require a high speed encryption for providing a high security and a privacy. The CHESS-64 based on various controlled operations is designed forsuch applications. In this paper, however, we show that CHESS-64 doesn't have a high security level, more precisely, we present two related-key differential attacks on CHESS-64. The first at-tack requires about 2⁴⁴ data and 2⁴⁴ time complexities (recovering 20 bits of the master key)while the second attack needs about 2³⁹ data and 2³⁹ time complexities (recovering 6 bits of themaster key). These works are the first known cryptanalytic results on CHESS-64 so far.

Keywords: Block Cipher, CHESS-64, Data-Dependent Operation, Data-Dependent Permutation, Differential Cryptanalysis, Related-Key Attack

Categories: E.3, L.4, L.7