Block cipher is an encryption method which the encryption algorithm operates on a plaintext block of n bits and produces a block of n bits ciphertext.
Block Cipher has \({2}^{n}\) possible different plaintext block to encrypt.
Nonsingular Transformation Nonsingular Transformation mean the encryption algorithm must be reversible (Nonsingular) to decrypt the ciphertext into the original plaintext.
The ciphertext must be unique for each plaintext block.
Example: Encryption block cipher with a plaintext block length n=4 bits and ciphertext, with \({2}^{4}=16\) possible input states
