Quality of Encryption Measurement of Bitmap Images with RC6, MRC6, and Rijndael Block Cipher Algorithms

RC6, MRC6, and Rijndael are three block cipher algorithms. Different types of Bitmap images are encrypted with each of the three encryption algorithms. Visual inspection is not enough on judging the quality of encrypted images. So, other measuring factors are considered based on: measuring the maximum deviation between the original and the encrypted images, measuring the correlation coefficient between the encrypted and the original images, the difference between the pixel value of the original image and its corresponding pixel value of the encrypted one, the encryption time and the throughput. These measuring factors are applied on the three encryption algorithms to evaluate images containing many high frequency components and others containing very large areas of single colors as an example of binary images. The results of the nominal electronic code book are not enthusiastic, so the Cipher Block Chaining and the output feed back modes are implemented and the results are compared.