Research On Image Encryption Algorithm Based On Hyperchaos And DNA Coding

Digital image is an important carrier of network communication in China.It plays a wide role in multimedia,electronics and network communication,and plays a great role in communication,medical treatment and other aspects.Therefore,the exploration and research of image encryption technology has become an important topic in the field of security.Due to the high redundancy between adjacent pixels in the image and the large data capacity,the encryption efficiency is inefficient when encrypted using traditional image encryption methods,so such methods are not suitable for the encryption of digital images.Chaos system and DNA computing make it exactly suitable for image encryption.Based on the current research status of image encryption algorithm,the following two algorithms are proposed to solve the problem of single coding rule and low information entropy.The main contents are as follows:(1)This thesis presents an image block encryption algorithm based on Chen hyperchaotic and DNA coding.The Logistic map is iterated first,the random sequence is obtained,and the sequence is transformed into a two-dimensional matrix.Then the parameters and initial values are changed,and the chaotic system is Logistic again to obtain a new random sequence.The index sequence is constructed to complete the scrambling and diffusion of the original image.Using the hyperchaotic Chen with many parameters and complex space,four chaotic sequences are obtained,that is,X?Y?Z?H.sequence The random value of X?Y sequence is used to control the selection of DNA coding rules,so that the coding has randomness and uncertainty.The transformed two-dimensional matrix and the diffused image are encoded in blocks to obtain the DNA matrix.Then the two matrices are DNA,which is determined by the random value of the sequence Z,and finally decoded according to the sequence H.Because of the different rules,the security is further strengthened and the final encrypted image is obtained.The algorithm can be used in image encryption field through experimental Simulation and security analysis.(2)An image encryption algorithm based on Wavelet transform,Qi hyperchaos were proposed,and DNA encoding.The algorithm first uses wavelet transform to decompose the image into high-frequency and low-frequency components,and then scrambles the low-frequency image was scrambled by constructing an index sequence.We obtain a scrambled image through Wavelet reconstruction,and then sets the parameters and initial values of the Logistic chaotic system.We preprocess the sequence generated after the iteration,use the preprocessed sequence to encrypt the image after Wavelet reconstruction.And then we set the initial value to iterate on the Qi hyperchaotic system,resulting in multiple chaotic sequences.We process the sequence to complete the key structure,and use the final sequence to double-encrypt the image.Finally,the encrypted image is encoded by selecting DNA encoding rules.And it performs DNA calculations with the DNA matrix transformed by the chaotic sequence,and we obtain the final ciphertext image by decode.The algorithm has been verified by simulation test and performance analysis that it can be used in the field of image encryption.