Let Block be a block cipher consisting of two rounds of a Feistel cipher having block length 8 with the session keys k1 and k2 such that k=k1||k2 be the secret key. Suppose the complex function F used in the Feistel cypher is simple AND with the session key. That is F (m, k) = m AND k for input string m and session key k. Find the ciphertext Block (m, k) where the message m =10100101 and the secret key k= 11001010.

Subject:Cryptography and network security