Research On Encryption For Fractional Order Fourier Domain Of Video Based On Cascaded Chaos

Today, with rapid development of Internet, the security of information transmission problems is more important.At present, there are two main problems in the FRFT and chaos encryption fields,which are that FRFT is rarely applied in real-time signal processing, and that the simplex theory of chaotic cryptography has not been yet entirely mature, most of chaotic encryption has still utilized natural chaotic system to encrypt, and many defects have been discovered in chaotic cryptography methods.To solve above problems, encryption for fractional order Fourier domain of video based on cascaded chaos is proposed. The properties of fractional Fourier transform is analyzed in the paper,the initial value sensitivity of chaotic system, the Lyapunov index chart and key distribution are studied. Then the overall system model is built, algorithm implementation process is described, video acquisition and transmission and encryption process function calls relations are described, the VC ++configuration is explained and the effect of encryption and decryption system is demonstrated.Meanwhile, in order to make better use of fractional Fourier transform video signal is encrypted, the paper also Fractional Fourier Transform twiddle factor sensitivity and chaotic system the initial parameters of the sensitivity of the system and fractional Fourier transform analysis done diffusion and use of its sensitivity and further proliferation of fractional Fourier domain ciphertext encrypted.The sensitivity analysis shows that the sensitivity of the fractional Fourier transform rotation factor is greater than 10-3, the initial value of the chaotic system and parameter sensitivity is reached10-15, which ciphertext attack against the brute-force method has an important significance. Diffusion analysis shows that when the ciphertext error rate exceeds 1.5%, will lead to its inverse transform to recover the original signal complete failure. Paper using fractional Fourier transform rotation factor sensitivity and diffusivity of fractional Fourier domain further cipher to encrypt, achieved the effect of dense on encryption, make its been deciphered the probability of reduced to 10-1878, to further strengthen the security of the system. Histogram analysis and correlation analysis show that the algorithm can effectively resist attacks statistical analysis class. Theoretical analysis and system test results show that the encrypted video has good resilience in the decryption process, and network delay is less than 1s, to meet the real-time requirements. Scheme is effective, safe, and simple, compared with the chaotic encryption or simple fractional Fourier transform encryption, increased the complexity of the algorithm, which is better than that of pure chaos encryption or pure fractional Fourier transform encryption method.