A new approach to measure quality of image encryption

Image encryption techniques are applied widely in the digital world today to assure information security. Although more and more encryption algorithms appear, they lack a method to evaluate the encryption quality. Visual inspection is not enough on judging the quality of encrypted images. So, we propose three classes of measurements based on the pixel’s position changing, value changing and both value-position changing. In order to evaluate the efficiency of methods, measurements were applied on three different chaotic image encryption algorithms based on the baker’s map, Arnold cat map and standard map. Experimental results indicate the performance of the measurement techniques in terms of producing results that are consistent with the judgment by visual inspection.