Double-image compression and encryption scheme based on chaotic system and real-preserving multi-order discrete fractional Fourier transform.

In order to reduce the amount of data transmission and key consumption, a double-image compression and encryption scheme based on chaotic system and real-preserving multi-order discrete fractional Fourier transform (RPMODFrFT) is proposed in this paper. It can compress and encrypt two images simultaneously, and the measurement matrix of compression sensing is controlled by 2D Logistic-Sine-Coupling map (2D-LSCM). After consolidating two compressed images into one image, the image is further encrypted by scrambling and 2D-LSCM controlled RPMODFrFT operation. At last, the bitwise XOR operation using 2D-LSCM with the initial value related to the plain image is carried out. The simulation results show that the proposed encryption-compression scheme has high security and robustness through a lot of attack analysis, i.e. differential attack analysis (NPCR > 99.6022% and UACI >33.5658%), entropy values (average 7.99710), statistical attack (correlation coefficient values are almost 0), noise attack and cropping attack. [ABSTRACT FROM AUTHOR]