Novel permutation measures for image encryption algorithms

This paper proposes two measures for the evaluation of permutation techniques used inimage en- cryption. First, a general mathematical framework for describing thepermutation phase used in image encryption is presented. Using this framework, sixdifferent permutation techniques, based on chaotic and non-chaotic generators, aredescribed. The two new measures are, then, introduced to evaluate the effectiveness ofpermutation techniques. These measures are (1) Percentage of Adjacent Pixels Count(PAPC) and (2) Distance Between Adjacent Pixels (DBAP). The proposed measures areused to evaluate and compare the six permutation techniques in different scenarios. Thepermutation techniques are applied on several standard images and the resultingscrambled images are analyzed. Moreover, the new measures are used to compare thepermutation algorithms on different matrix sizes irrespective of the actual parametersused in each algorithm. The analysis results show that the proposed measures are goodindicators of the effectiveness of the permutation technique