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.