A Color Image Encryption Algorithm Using a New 1-D Chaotic Map

This paper presents a color image encryption algorithm using a new 1-D chaotic map, tent-logistic map, which is produced by a cascade chaotic system (CCS). Compared with corresponding seed maps, the employed chaotic map has more parameters and complex chaotic properties while remaining simplicity, making it a good candidate for constructing image ciphers with a sufficiently large key space and high computational efficiency. In the permutation stage, the positions of colored subpixels in the input image are scrambled using a pixel-swapping mechanism, which effectively avoids the periodicity problem encountered by discretized version of area-preserving chaotic maps. To strengthen the robustness of the proposed algorithm against chosen-plaintext attack and increase the diffusion intensity, a mechanism for associating keystream sequence with plain-image is introduced during the substitution process. The results of NPCR and UACI tests indicate that the proposed algorithm takes only two cipher rounds to achieve a satisfactory diffusion effect. The security of the proposed algorithm is analyzed in detail, and the results demonstrate its satisfactory level of security.