An Image-Encryption Algorithm Based on Stage-Merging Bit Scrambling

At present, the existing single-pixel position-scrambling technique is not sensitive to the chaotic sequence used, and adjacent-pixel position scrambling has difficulty ensuring a good scrambling effect and speed at the same time. In this paper, a stage-merging scrambling algorithm is proposed, which combines the two-stage scrambling process and can complete the dual scrambling of pixel position and pixel value at the same time. It not only improves the scrambling speed, but also greatly improves the scrambling effects. Then, a complete image encryption and decryption scheme was designed based on stage-merging bit scrambling combined with DNA coding. Security analysis shows that the algorithm can resist various means of attack such as exhaustive attack and differential attack. The research in this paper extends the existing bit-scrambling algorithms and is suitable for practical applications.