| 摘要 |
A method and apparatus provide encryption, decryption and authentication of messages using dynamical systems. The method and apparatus preferably operate on an information stream which may comprise message information, authentication information, and random or pseudo-random information. The initial secret keys of the system are a collection of dynamical systems, at least one of which is irreversible. These keys operate on states of the dynamical systems into which the message has been encoded. To initialize the encryption, a subset of the secret keys are selected to be current keys, and the desired message is encoded into the initial states. Encryption continues over a plurality of cycles. During each cycle the current keys are applied either backward or forward in time to their current states, over a plurality of sub-cycles. If during an encryption cycle an irreversible dynamical system is iterated in the backward direction, the choice of antecedent states may either be made randomly or according to information from the input information stream. After all encryption cycles have been performed, the current states of the dynamical system constitute the ciphertext. The ciphertext may then be decrypted by a method similar to the encryption method. In the preferred embodiment, random noise is diffused into the plaintext during encryption, and eliminated during decryption. The apparatus of encryption and decryption in the preferred embodiment operates with parallel hardware using only bit operations and table lookup; it may thus be made to operate in an exceedingly fast manner.
|
