Color Image Encryption Schemes Based On Chaos And DNA Sequence

Nowadays,digital image information is widely spread on the Internet and is easy to suffer from a large number of malicious attacks.Therefore,the security of image information becomes particularly important,which promotes the rapid development of image encryption technology.Two color image encryption schemes are designed based on chaotic system and DNA sequence.The main work is as follows.(1)A color image encryption algorithm is designed based on DNA sequence cyclic complement operation.The initial value of the algorithm's chaotic system can be generated by the SHA-256 hash value of the plaintext image,which makes the algorithm effectively resist the selection of plain text attacks.In the scrambling stage,the R,G,and B components are combined into a new pixel matrix,and the chaotic sequence generated by the coupled map lattice(CML)is used to index the scrambling,thereby increasing the scrambling space of each pixel and reducing the Strong correlation between components.In the diffusion stage,the pseudo-random numbers generated by the chaotic sequence select DNA coding rules,which complicates the encryption scheme.Use the Hamming distance to update the key,and formulate four DNA cyclic complement operations for pixel diffusion,so that the pixels between the three components can be diffused each other.Simulation results and performance analysis show that the encryption algorithm can resist various known attacks.(2)A color image encryption scheme is proposed based on chaotic system and DNA sequence.Different from the traditional scrambling and spreading encryption mode,this encryption scheme uses the "Forward Diffusion-Scrambling-Backward Diffusion" encryption mode.In the forward diffusion,the R,G,and B components are subjected to DNA XOR operation with the chaotic matrix after DNA encoding,so that each component contains a random component,which reduces the correlation between pixels within each component.Then randomly add R,G,and B components to each other by DNA addition,subtraction,and XOR operation,so that the pixels of each component can be hidden into other components.In the scrambling stage,the three components are combined into a matrix for scrambling operations,which increases the scrambling space of the pixels and reduces the strong correlation between pixels within the components.In backward diffusion,a binary XOR operation is performed on the R,G and B components.Simulation results demonstrate that the encryption scheme has high sensitivity in plaintext.