Research On Visual Image Encryption Algorithm Based On Compressed Sensing And Chaotic Syste

The advancement of information and network technology has produced a large number of data carriers such as digital images and videos,and at the same time privacy protection has received more and more attention.Therefore,in the fields of military security,medical image processing,network transmission,etc.,the image encryption system has attracted much attention.The noise-like or texture-like images generated by traditional image encryption technology will increase the attack probability of hackers during the transmission process.To solve this problem,this paper studies the visual image encryption algorithm.The cipher image generated after the image is visually encrypted is visually visible,that is,a visually meaningful image,which can effectively avoid the attention of attackers,thereby improving the security of the transmission process.With the development of the times,the data volume of digital images is increasing,and more and more attention is paid to storage efficiency,transmission security and faster computing speed when encrypting images.As a new sampling and reconstruction algorithm,Compressive Sensing theory is widely used in image encryption algorithms,but image encryption algorithms that only use compressed sensing are not safe,and the initial value of sensitivity,randomness,and long-term unpredictability of chaotic systems consistent with cryptography standards.Therefore,applying the combination of chaotic systems and compression awareness to visual image encryption frameworks is of great research value.Keeping this in mind,this paper proposes two visual image encryption algorithms,the main research content is as follows:(1)A visual image compression encryption algorithm based on four-dimensional discrete chaos and Latin rectangle scrambling is proposed.First,in order to reduce the complexity and improve the efficiency of the algorithm,a simple method for constructing a four-dimensional discrete chaotic system is proposed,and a four-dimensional chaotic system is constructed.Secondly,the entropy value of the normal image is used to generate the initial value of the chaotic system as a key,and the algorithm and code are used to generate the metric matrix and password string required for encryption.Then,to improve the security of cryptographic systems,a Latin rectangle generation and scrambling algorithm based on chaotic sequence is designed to encrypt the compressed and measured image to generate a secret image.Next,the cover image is decomposed using discrete wavelet transform and the secret image is embedded into it to generate a visually visible secret image.Finally,the performance of the algorithm is analyzed qualitatively and quantitatively,and the security and anti-attack of the proposed algorithm are analyzed and verified.(2)A visual image compression encryption algorithm based on mixed chaotic bipolar measurement matrix is proposed.In this algorithm,a mixed chaotic binary measurement matrix is constructed,and it has better performance than other measurement matrices at low compression ratios.To solve the problem that the traditional image encryption algorithm cannot withstand the plaintext attack,the SHA-256 value of the original image is used as the initial value of the discrete chaos mapping system,and the image is scrambled and bidirectionally diffused.In order to recover the secret image accurately and reduce the pressure of channel transmission of the encrypted image,a new image embedding method is proposed,which converts the secret image into a binary representation and embeds it into the carrier image after discrete wavelet transform one by one.Finally,the encryption algorithm is simulated and analyzed to verify the high reconfiguration,invisibility and attack resistance of the proposed algorithm.