Image Encryption Algorithm Based on Chaotic Mapping and Binary Bidirectional Zigzag Transform

With the continuous development of chaotic systems, they have increasingly become the core of the field of image encryption, and the good performance of chaotic systems is crucial for image encryption. Some two-dimensional chaotic maps still have drawbacks such as uneven distribution and small key space, which are prone to destruction. To this end, a new two-dimensional logic infinite folding iterative mapping is proposed, and an encryption algorithm is designed based on this. Experimental analysis shows that the chaotic map has good chaotic characteristics. Secondly, a binary bidirectional zigzag transform image scrambling algorithm is proposed. Compared with traditional zigzag transform, binary bidirectional zigzag transform has more sufficient dislocation effects and greatly reduces the correlation between adjacent pixels in the image. Finally, a bidirectional diffusion algorithm was used to destroy the image completely, making it difficult to be deciphered. Besides, the combination of the SHA-256 algorithm with the plaintext image provided better resistance to plaintext attacks. Experimental simulations illustrate that the encryption algorithm can effectively resist various attacks with high security and is not easy to crack.