The Properties of Closed State Evolutive Ring in Random Permutation-Table and Its Application to Block Encryption

In this paper the concept of random permutation table is presented from F table in Skipjack block encryption. The probabilities and the expected values of closed state evolutive ring numbers and the average length of state evolutive rings are studied and their closed forms used in computation are given. For quick computation their recurrence forms are obtained. The theoretical results are proved experimentally by numerical simulation.