Image Encryption Algorithm with Block Scrambling Based on Logistic Map

Abstract

Abstract Objectives: To develop an efficient algorithm based on block-scrambling and chaotic maps to generate an encrypted image capable of protecting sensitive information. Methods: The proposed technique introduces the two- pass Block-XOR operation column-wise and then swaps pixels within each block in an anti-clockwise crisscross pattern to separate and rearrange nearby pixels into distinct rows and columns. The strong correlations between nearby pixels are disrupted, making it challenging to identify the original image. Afterward, image diffusion using binarization is performed on the obtained scrambled image using a chaotic sequence generated by a logistic map. Findings: This scheme has accomplished an efficient encryption method based on block-scrambling and a chaotic map. The experimental results show that the system is competent for generating cipher text by encrypting images and can withstand malicious attacks and thus protect sensitive information. The histogram analysis results show that the proposed system displays adequate resistance to statistical attacks. The histogram of cipher text is uniformly distributed and bears no resemblance to the plaintext histogram. The differential analysis shows that the NPCR and UACI values are greater than 99 and 33, respectively, and are acceptable to conclude that the system is also resistant to differential attacks. The proposed technique experimented with using standard test images from the literature and the USC-SIPI image dataset. Novelty: A two-pass Block-XOR operation strengthens the scrambling by altering the value of the image pixel. Then an anti-clockwise crisscross pixel swapping algorithm is utilized for block scrambling.