E-mail Encryption Based on Dual Chaotic Map

Single chaotic system which is realized with limited precisions in digital computers can lead to dynamical degradation of the original systems. To solve the dynamical degradation problem, this paper introduces a new kind of dual chaotic encryption algorithm which is constructed via a Logistic map and a Sine iterative map. Digital PR sequence is generated using the dual chaotic system, and then an E-mail encryption system based on the dual chaotic encryption algorithm is implemented by using VC++ language. In comparison with single chaotic system, dual chaotic system can expend control parameters to increase complexity of chaos behavior so as to improve the security of E-mail encryption. In order to evaluate the security of the encryption algorithm, the proposed sequence is tested by NIST (National Institute of Standards and Technology), and the PR sequence successfully passes the statistical tests. Theoretical analysis and experimental results show that the proposed algorithm has some properties such as easy to operate, high sensitive to initial conditions, large key space and so on.