Let a ⊕ b denote the bitwise exclusive-or of two binary arguments: a, b.
The one-time key encryption system is defined as follows:
First, we specify the integer l > 0. We then define the spaces of the message M, key K, and ciphertext C. They are all equal to {0, 1} l.
The key generation algorithm works by selecting the binary string K = {0, 1} l according to the uniform probability distribution.
Encryption works as follows: we use the key k ={0, 1} l and the message m ={0, 1} l where the result is defined as c =k ⊕ m.
The opposite operation is as follows: we give the key k = {0, 1} l and the ciphertext c = {0, 1} l.
For the final we get m = k ⊕ c.