Cryptography with cycling chaos

Periodic switching of cryptographic keys is commonly employed as a mechanism to enhance the security of encryption methods. In this Letter, cycling chaos, in which orbits of certain coupled iterated maps make periodic excursions between chaotic sets, is proposed as a new encryption approach that combines chaotic behavior with periodic switching of keys. The actual encryption process is similar to the one used by Baptista [Phys. Lett. A (1998) 50], except that now different chaotic attractors, and consequently different keys, are periodically switched to encrypt each character of a message. Advantages and disadvantages of this approach are also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.