Security on Generalized Feistel Scheme with SP Round Function

This paper studies the security against differential/linear cryptanalysis and the pseudorandomness for a class of generalized Feistel scheme with SP round function called GFSP. We consider the minimum number of active s-boxes in some consecutive rounds of GFSP,i.e., in four, eight and sixteen consecutive rounds, which provide the upper bound of the maximum differential/linear probabilities of 16-round GFSP scheme, in order to evaluate the strength against differential/linear cryptanalysis. Furthermore, We investigate the pseudorandomness of GFSP, point out 7-round GFSP is not pseudorandom for non-adaptive adversary, by using some distinguishers, and prove that 8-round GFSP is pseudorandom for any adversaries. Key words: Differential cryptanalysis, Linear cryptanalysis, Branch number, Cipher, S-box, Pseudorandomness.

• Type: Journal
• Year: 2006
• Where: IJNSEC
• Authors: Wenling Wu, Wentao Zhang, Dongdai Lin
• Keywords: Consecutive Rounds, Cryptanalysis, Feistel Scheme, IJNSEC 2006