An Encryption Method Based on Dual-Chaos System

Chaos is extremely suitable for applying in information security domain due to its excellent cryptography characteristics. But, computer limited precision expression and unitary chaos with simple structure being easily threatened by chaos reconstruction restricted its practical application. To solve the problem, a new kind of dual-chaos encryption alogorithm which take Logistic mapping as chaos model has been designed and realized. Fibonacci sequence is adopted for mapping chaos to integer space in order to solve limited precision expression problem, dual-chaos system expend control parameters and increase complexity of chaos behavior so as to resiste attacktion of chaos reconstruction. Besides dual-chaos trajectory, length of palintext is introduced as a new control parameter participating in encryption process, overcame disadvantage of key sequence only determinated by user password, further strengthens security performance of the algorithm. Considering Chinese character storage structure, double-byte encryption is employed to extend key space. Theoretical analysis and experiment results indicate that the proposed algorithm has excellent robustness and it´s encryption effect is perfect.