A Fast Discrete Cosine Transform and a Cryptographic Technique for Authentication and Security of Digital Images

Abstract

In a cyberspace where disparate applications are engaged in multimedia transmission, data compression is a key for maintaining bandwidth usage efficiency as well meeting the data requirements of the disparate applications. Security of data in such environment needed to be guaranteed. Cryptographic approaches engaged in the process have to be efficient enough to stand against attacks and also to maintain important visual continents after compression. In our work, we proposed a fast discrete cosine transform and a cryptographic technique for authentication and security of digital images. The cryptographic approach was applied to the image after compression, and before decompression, the image was successfully decrypted without significant loss of visual data. There was a loss in pixel values due to the compression process. The implementation of the proposed approach was done successfully and analysis of the output results was done using MATLAB.