Block cipher Definition An n-bit block cipher is a function E:V×Kn, such that for each key K∈K E(P; K)is an invertible mapping (the encryption function for k) from vn to vn, written Ek(P). The inverse mapping is the decryption function denoted Dk(C). P denotes that ciphertext results from encrypting plaintext P under KBlock cipher Definition An n-bit block cipher is a function E : VnK→Vn , such that for each key K K, E(P;K) is an invertible mapping (the encryption function for K) from Vn to Vn , written EK (P). The inverse mapping is the decryption function, denoted DK (C). P denotes that ciphertext results from encrypting plaintext P under K