i. Consider an SPN (Substitution Permutation) cipher on input x, with number of rounds being…

i. Consider an SPN (Substitution Permutation) cipher on input x, with number of rounds being indictated by Nr. Prove that if the last round has a permutation layer then it does not increase the strength of the cipher. ii. Consider an invertible Substitution operating on m bits, where m is an integer. Prove that it is a permutation from {0, 1} m to {0, 1} m.