Image encryption using mapping array and random division

This paper presents a fast image encryption algorithm. It divides the input image into four overlapping blocks by choosing a random rectangle, and then randomly selects an encryption order of these blocks. Next, it exploits random swap technique to generate mapping arrays. Finally, it uses different mapping arrays to perform block encryption, and writes the encrypted result to its original position before processing the next block. Theoretical analysis and experimental results show that the proposed algorithm is faster and more secure than conventional Arnold transform. It has no size limitation and can be applied to any size images. © 2011 ICIC International.