Encryption using random keys-a scheme for secure communications

An encryption scheme using a random key generator with memory is presented. This system generates a random sequence of encryption/decryption keys. A feedback mechanism is used to endow the key generator with memory, thereby making it difficult to infer the random key sequence from a partial sequence of keys. The random key sequence is independent of the encrypting algorithm and is particularly suitable for block encryption. An information-theoretic entropy measure of cryptologic hardness is developed and an upper bound for this measure is established. The proposed scheme is compared with some existing cryptographic schemes and it is demonstrated that the proposed scheme and its variants are more attack resilient and are capable of achieving the theoretical upper bound