The Vernam cipher requires a key with the same length as the original data. For decrypting data, the same algorithm can be used - it's symmetric. Even with increasing computing power, it can't be broken.ĭue to the fact that encryption is done by XOR, the algorithm is pretty fast. The security of one-time pad, on the other hand, is based on the unique use of the key and sufficient randomness of the used key. In other words, a potential attacker lacks the necessary resources (computing capacity or time) to perform his attack successfully. Other encryption methods (such as AES) achieve their security with the immense burden of calculating theoretically conceivable decoding, which is practically not feasible. For decrypting, only the secret key and the encrypted data is used. The Vernam cipher with one-time pads is the only known encryption procedure where, in theory, information is secure and can't be deciphered, if the key is randomly and only once used for encryption. A widely used implementation of the Vernam cipher is RC4. When the stream of data used as key is truly random and used only once, it is called a one-time pad. Vernam cipher is a stream cipher where the original or plain data is XORed with a random (actually pseudorandom) stream of data of the same length to generate the encrypted data. This kind of encryption is truly unbreakable as long the key is maintained a secret.

In this article, I'll show how to do a simple but robust encryption/decryption, with the algorithm of Gilbert Sandford, Vernam.

Vernam encryption algorithm