Degradation Analysis,Optimization Strategy And Application For The Digital Chaotic Systems

Chaotic system has the characteristics of initial condition sensitivity,ergodicity,stretching folding transformation,positive lie index and strange attractor.These characteristics of chaotic system are closely related to the features of diffusion and confusion in modern cryptography,and it has a great application value in cryptography.In recent years,chaotic secure communication has attracted widespread attention.However,although a large number of papers on the design and analysis of chaotic ciphers have been published,the chaos-based ciphers still takes a long time to be applied in a large scale.There are mainly two categories of security problems in chaotic cryptography: The structure of the encryption algorithm and the chaotic system.Among them,the chaotic system is mainly due to the fact that the chaotic system will produce the dynamical degradation when a chaotic system is implemented on a computer or other device with limited precision.This phenomenon will greatly destroy the security of the cryptosystem based on chaotic systems,and hindering its development in practical applications.First of all,in order to overcome the dynamic performance degradation phenomenon of the digital chaotic system with finite precision,different from other methods that use the m-sequence or some digital chaotic system as the disturbance source,this paper uses the continuous chaotic system Chen as the disturbance source,and the output of the Chen chaotic system is used to perturb the Chebyshev parameters and input of the digital chaotic map,and the digital Chebyshev system is compensated by the trajectory of the Chen system.Based on this improved scheme,a pseudorandom number generator with a good randomness was designed.Finally,the improved system model and the pseudo-random number generator are tested by simulation.Secondly,this paper uses the unscented Kalman filter(UKF)algorithm and the disturbance feedback technology hybrid operation to improve the dynamic performance degradation of the chaotic system.The UKF algorithm is used to predict and estimate the approximate ideal digital chaotic sequence.Then,perturbation scheme is used to carry out disturbance feedback to the predicted value,which makes the final output obtain a higher randomness and security,and it can resist the attack such as phase space reconstruction.In this improved method,one-dimensional and three-dimensional chaotic systems were used to verify the results.The simulation results show the effectiveness,superiority and robustness of the proposed method.Finally,a pseudo-random number generator is designed based on the previous example,and the test shows that it has superior performance.Last,the digital signature technology suitable for wireless sensor networks is designed by using the semi-group property of chaotic mapping Chebyshev polynomials and corresponding mathematical computing problems;and a new hash function is designed using the chaotic system generated by the chaotic degradation improvement scheme designed by the first research project.The improved chaotic scheme is used as an integer operation,and it is used as the compression iterative function of the hash function so that the designed hash function is suitable for a wireless sensor network with limited node resources.Combined with the digital signature scheme and hash function scheme,a broadcast based identity authentication scheme based on chaos in wireless sensor networks is finally constructed.The protocol is implemented on the hardware platform CC2530,and various performance tests and power analysis are given.