Consider the affine cipher with key k = (k1, k2) whose encrypti... | Filo

if an encryption function ex is identical to the decryption function dx then the key is said to be an involutory key find all involutory keys ab in the affine cipher ex ax b mod 15 ie over z 45504

A generalization of the Caesar cipher, known as the affine Caesar cipher, has the following form: For each plaintext letter p, substitute the ciphertext letter C : C=E([a, b], p)=(a p b) 26 A basic requirement of any encryption algorithm is that it be one-to-one. That is, if p ≠q, then E(k, p) ≠E(k, q). Otherwise, decryption is impossible, because more than one plaintext character maps into the same ciphertext character. The affine Caesar cipher is not one-to-one for all values of a. For example