Some Observations on MISTY Structure With SPN Round Function
MISTY structure is a kind of block cipher structure that can provide provable security against differential and linear cryptanalysis. In this paper, the authors present some distinguishing properties of MISTY structure with SPN round function. They first show the existence of 6-round integral distinguishers when the linear transformation in the diffusion layer is binary. Then they discuss how to characterize 5=6=7-round impossible differentials through the matrix-based method. According to the analysis, the distinguishing bounds on the block cipher p-Camellia which is proposed at Africacrypt 2010 can be improved.