International Association for Cryptologic Research (IACR)
Abstract
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