Image encryption scheme based on optical chaos and DNA Rubik’s cube algorithm

Abstract

Abstract In order to improve the complexity of optical chaotic sequence output and the encryption efficiency of bit plane encryption, an image encryption algorithm based on optical chaos and DNA Rubik’s cube scrambling is proposed. An external disturbance structure of light injection is proposed to improve the complexity of the chaotic sequence of light output from the slave laser by the external disturbance generated by the mutual injection between the driving laser and the main laser. Meanwhile, in the image algorithm, in addition to Rubik’s cube scrambling at the pixel level, this paper proposes a bit plane encryption method based on DNA plane Rubik’s cube scrambling, which reduces the amount of encrypted data and further improves the security of image encryption by using encryption selection of different DNA encoding modes. The scrambled images are diffused by DNA calculation and optical chaos sequence at the bit-level and pixel level respectively. Through the quantitative analysis of the security simulation of the proposed algorithm, the results show that the algorithm guarantees a certain encryption efficiency under the condition of good security, the key space is 1064, the information entropy of each test ciphertext image is close to the theoretical maximum, and the test indexes of plaintext sensitivity and key sensitivity are close to ideal values. For differential attacks, chosen plaintext attacks, known plaintext attacks, exhaustive attacks, cropping attacks, and noise attacks have good robustness.