Abstract: A method, system, and computer program product are provided for encrypting and decrypting information, such as electronic mail. Each party has a secret, unique, randomly assigned value y. A sender and receiver first engage in a preliminary message exchange, or “handshake. ” At this point, the sending party is given the y value of the receiving party. A key is then generated randomly or pseudo-randomly by the sending party. The key is used to encrypt a byte of information to be sent to the receiving party. A new key is generated for every byte to be encrypted. The resulting ciphertext is a combination of the output of a function F and a function P. F is a function of plaintext and the key. P is a function of the plaintext and the y value of the receiving party. During operation, y values and keys are not readily apparent to users.