Construction of Zero-correlation Linear Hull for CLEFIA-like Structure with SPN Round Functions

Zero-correlation linear cryptanalysis is a newly proposed attack of block ciphers. The first step of this cryptanalysis is to construct a zero-correlation linear hull whose correlation value is 0. This paper investigates the construction of zero-correlation linear hull for CLEFIA-like structure with Substitution-Permutation (SP)-type round function. And a new method of finding (4n+1) round zero-correlation linear hull of this structure is proposed. By the proposed method, large amount of zero-correlation linear hulls of 9 round CLEFIA are obtained.