The idea of combining synchronous chaotic systems with classic cryptography has been presented. A chaotic system sends a driving signal to two chaotic slave systems which have no influence on the generating of the driving signal. These two slave systems are synchronized and used to generate secret keys. The secret keys can be considered as pseudorandom. They are used only once and are not shorter than the message length. In this way, the idea of chaotic cryptography has been demonstrated. Its main advantages include easy implementation and good privacy.

• Received 27 August 1997

DOI:https://doi.org/10.1103/PhysRevE.57.1532