Application of data encryption standard to bitmap and JPEG images

This paper investigates the performance of the application of data encryption standard as a popular encryption scheme to two schemes of images the bitmap image which is the best choice for representing subtle gradations of shades and color such as screen shots or simple painted images and the JPEG image which is the best choice for continuous tone images such as photographs. The method of application of DES on the image in each case is explained. Previous studies on image encryption although scarce judge the quality of encryption by mere visual inspection. However, a measure for encryption quality is introduced and applied to a selected number of different images. Generally it is shown that application of DES to JPEG images produces better results than to BMP ones.