Digital Image Encryption Based On Chaos Theory And DNA Coding

The transmission of encrypted data can effectively protect the data information,because there are many security vulnerabilities in the complex network environment.Image data contains a large amount of information.The standard AES algorithm needs a large number of security keys to encrypt the image,and it has high computational complexity.Chaotic system can generate a large number of security keys,which is due to its high sensitivity to the initial value.DNA sequences can carry a lot of image information.Based on the study of chaos theory and DNA coding technology,two new image encryption schemes are designed.The first encryption scheme introduces a four-dimensional hyperchaotic system,which can obtain a secret key space of 2225.An encryption scheme including permutation-diffusion-permutation is proposed.In the first part,Arnold map is used to scramble the order of pixels and hide the association information of adjacent images.In the second part,a wheel structure diffusion algorithm is designed based on Feistel network.In each round of operation,only one side of the data is encrypted and interfered by the unencrypted side.The advantage of this structure is that the encryption and decryption steps are the same.In the third part,one-dimensional random permutation is performed,which interferes with the combination and arrangement of pixels again.Simulation results show that the encryption scheme can effectively resist a variety of typical malicious attacks.The second encryption scheme is based on one-dimensional Logistic and Sine chaotic maps,which are extended to three-dimensional.Performance evaluation shows that the chaos has good ergodicity and orbit uncertainty.A DNA random coding scheme is proposed,whose coding rules strictly depend on chaotic sequence and make full use of the randomness of chaotic map.Further,a new image encryption scheme is proposed,which adopts permutation,forward diffusion,and reverse diffusion.The simulation results show that the scheme can effectively resist a variety of typical attacks,especially in the anti-differential attack and anticropping attack.