Abstract
Implementation of the RC5 block cipher algorithm for digital images in different modes of operation and its detailed encryption efficiency analysis are dealt with in this paper. The encryption efficiency analysis of the RC5 block cipher algorithm for digital images is investigated using several metrics including visual testing, maximum deviation, irregular deviation, information entropy, correlation coefficients, avalanche effect, histogram uniformity and key space analysis. The evaluation consists of theoretical derivations and practical experimentation. Experimental results have proved that the RC5 block cipher algorithm can be implemented efficiently for encryption of real-time digital images and demonstrated that the RC5 block cipher algorithm is highly secure from the strong cryptographic viewpoint.