ABSTRACT
Chaos theory is the study of dynamic systems that evolve in time presenting properties such ergodicity, sensitivity to initial conditions, topological mixing etc. In recent years quite a number of researches on chaos based cryptosystem have been proposed. However, most of them encounter some problems such as: low level of security and small key space. The key stream generator is the key design issue of an encryption system. A remarkable characteristic of chaotic systems is their capability of producing quite complex patterns of behaviour from Simple real systems which makes it suitable to be used in cryptosystems. This paper presents an approach for the application of Chaos Theory in symmetric key cryptography by implementing and analysing an algorithm based on the concepts of Chaos Theory giving special focus on key generation.