An encryption scheme that uses steganography includes an encryption algorithm that encrypts messages by embedding them in a data stream in such a way that an adversary cannot get information about the messages. Since the embedding is the only computation required, this scheme is optimal in computational efficiency. However, since the size of the data stream is large, this scheme is most beneficial when the cost of bandwidth is less expensive than the cost of computation. The scheme embeds the message as specified by a pseudo random generator.