Research On Image Encryption Based On Chaos And DNA Codin

With the rapid development of science and technology,the rapid dissemination of information,and the increasing scale of internet users,the world has become rich and colorful.At the same time,security issues such as information dissemination,leakage,and tampering in open channels are also becoming increasingly serious,making it urgent to improve the security of information.One of the common methods to improve security is encryption.As one of the important information carriers,images have the characteristics of high redundancy and high correlation.The original information encryption technology has problems such as insufficient sensitivity to keys and ciphertext,and long encryption time.With the emergence of chaos theory,chaos has the characteristics of initial value sensitivity,pseudorandomness,etc.,which can enhance the sensitivity of key and ciphertext.Therefore,the security of image encryption technology is improved;Meanwhile,the parallel nature of DNA encoding operations can reduce the running time of image encryption algorithms and promote the development of image encryption technology.Although there are many existing image encryption algorithms,there are problems such as low complexity of chaotic sequences,weak sensitivity between keys and plaintext,high memory overhead,and slow algorithm speed.This article constructs a new chaotic system and verifies it to address the above issues.Firstly,a new system GPHM is constructed using a linear combination of sine function and H e non mapping to enhance the complexity of chaotic sequences.The GPHM system has been validated by the maximum Lyapunov exponent,permutation entropy,and global boundedness of orbits,proving that it is a discrete-time chaotic mapping system;Secondly,comparing GPHM with generalized three-dimensional H é non mapping,3D-PHM,and H e non mapping,the results show that the system has four advantages:firstly,it has high behavioral complexity compared to the chaotic sequences generated by 3D-PHM;Secondly,when the number of iterations reaches 10000,the spectral entropy value is larger and the system structure complexity is higher;Thirdly,the generated chaotic sequence has passed NIST SP 800-22 detection,resulting in higher pseudorandomness of the sequence generated by the system;The fourth is that the approximate probability density test has been passed,and the distribution of the system trajectory in space is more uniform.In this paper,a new image encryption algorithm is designed by using the neotectonics GPHM chaotic system and DNA coding.Firstly,DNA encoding is performed on the plaintext and its hash value,followed by XOR operation to achieve the first round of diffusion;Next,by using the hash value of plaintext and the set initial value,the initial value of the GPHM system is jointly established.The key stream is obtained through iteration,and the key stream is combined with the improved Fisher Yetz random scrambling algorithm to achieve image scrambling;Finally,the key stream is reshaped to achieve a second round of diffusion and obtain the final encrypted image.The results show that the algorithm can resist the following attacks:firstly,with a key space of 2384,it can effectively resist violent attacks;The second is that the minimum entropy value of the ciphertext is 7.992,the minimum NPCR value is 99.59%,and the minimum UACI value is 33.39%,which is closer to their respective theoretical values(8,99.61%,33.46%)compared to other algorithms.Moreover,the correlation between adjacent pixels in the ciphertext image approaches 0,and its value is lower compared to other algorithms,which can resist statistical attacks;Thirdly,under salt&pepper noise,Poisson,andspeckle noise attacks,it can retain the main information of plaintext and resist noise attacks;Fourthly,ciphertext images can be restored after undergoing ordinary and random cutting,and can resist crop attacks;The fifth is to achieve one-time encryption through SHA,which enhances the sensitivity between the key and plaintext,and has the ability to resist special image attacks,thus being able to resist plaintext attacks.Therefore,the designed algorithm further enhances the security of image information dissemination.