In cryptography, the one-time pad (OTP) is a type of encryption that is impossible
to crack if used correctly. it also means The unbreakable encryption method.
The One Time Pad encryption method is a binary additive stream cipher,
where a stream of truly random keys is generated and then combined
with the plain text for encryption or with the ciphertext for decryption by
an ‘exclusive OR’ (XOR) addition.
The key must be as long as the plain text.
The key must be truly random.
The key must only be used once.
One Time Pad keys are used in pairs. One copy of the key is kept by each user and
the keys are distributed securely prior to encryption.
With One Time Pad encryption, the key used for encoding the message is completely
random and is as long as the message itself. That is why the only possible attack to
such a cipher is a brute force attack.