Research On Image Encryption Algorithm Based On Chaotic System

The development of computer and Internet technology has greatly facilitated the transmission of information,and nowadays multimedia data is widely used.However,due to the openness of transmission environment,kinds of attacks such as theft and tampering pose a great threat to the security of information.As a main carrier of information,digital image plays an important role in medical,military and other fields,its security has attracted much attention.Image encryption technology is an effective method.Image has many characteristics such as bulky data capacity and high redundancy,which make traditional encryption methods like DES,AES no longer applicable.The properties of chaotic system such as high sensitivity to initial condition,pseudo-randomness and ergodicity can meet the requirements of image encryption and bring advantages in security and efficiency,making chaotic image encryption an important branch of image encryption.With the increasingly high requirements on performance of image encryption algorithm,chaotic system is developing towards high-dimension and hyper-chaotic,and the realm of chaotic image encryption is growing wider and wider.The paper firstly introduce chaos theory,basic knowledge of cryptography and the application of chaotic system in image encryption,then focus on the chaotic image encryption combining with DNA computing and compressive sensing.On the basis of domestic and foreign related research,two image encryption algorithms are proposed with theoretical analysis and simulation experiments.An image block encryption algorithm based on chaotic system and DNA code operation is proposed.To solve the problem that the mode of DNA encoding and operation is limited,the object to be encrypted changes from whole image to image block.Complexity of the algorithm is increased by using pseudo-random sequence generated by hyper-chaotic system.The algorithm also has similar effect of one-time-one-key.The simulation experiments and security analysis demonstrate that the algorithm has ideal encryption effect and resistance to kinds of attacks.A double-image encryption algorithm based on chaotic system and compressive sensing is proposed.The algorithm can accomplish encryption and compression of image simultaneously,the two plain images are interrelated during the process.Encryption effect of measurement and permutation confusion based on hyper-chaotic system can protect the security.Results and analysis of simulation experiments demonstrate that the proposed algorithm has good encryption effect and compression performance.