Visual image encryption algorithm based on compressed sensing and 2D cosine -type logistic map

A new two-dimensional cosine-type Logistic map (2D-CTLM) is proposed in this paper. Performance analysis shows that 2D-CTLM has good ergodicity, complex behavior, and a wide range of chaotic regions. To study its application, an adaptive embedded high visual security image encryption scheme is proposed by combining the system with two-dimensional compression sensing to address the shortcomings of fixed embedding positions and low transmission efficiency in existing schemes. The embedding position is fixed when the ciphertext image is embedded into the carrier image. When embedded in an inappropriate location, it will affect the decryption quality and the imperceptibility of the steganographic image. Firstly, the initial value of 2D-CTLM system is generated by using the information entropy of plaintext image and counter to generate random measurement matrix, which is used to compress and encrypt plaintext image from two directions at the same time. Secondly, the compressed cipher image is scrambled by the initial matrix generated by the GOL (game of life) rules in two-dimensional cellular automata to obtain the ciphertext image. Finally, the most suitable embedding position in the carrier image is found by combining information entropy and edge entropy. Then the unquantized ciphertext image is embedded into it by ST (slant transform) embedding method to obtain a high visual security image. To improve the transmission efficiency, the color carrier image can be selected to transmit three gray plaintext images at the same time, maintain high-quality reconstruction effect. SHA-512 and the information entropy of plaintext image are used to generate the initial value of encryption and measurement matrix, enhance the correlation between the algorithm and plaintext image, and effectively resist known plaintext and selective plaintext attacks. Simulation results and performance analysis show that compared with the existing encryption schemes, the encryption scheme has excellent visual effect, good decryption quality and good robustness.