Prime Product Encoding for Lossless Compression and Encryption of Multiple Images

The paper explores the idea of joint image encryption and lossless compression. Based upon an exhaustive literature survey, a research gap is identified and addressed using the novel prime product encoding technique. The encoding is a security centric image encoding scheme based upon prime numbers. An integrated multi-image lightweight encryption and lossless compression framework is presented in this paper that uses state of the art cryptosystem for key exchange and block permutation over encoded domain, based approach for ensuring image secrecy. The encoding itself may be tweaked as per the levels of security and compression required. For encryption, only block permutation is used as the input image is already encrypted being in compressed domain. Performance analysis is discussed using noise analysis, key space analysis, PSNR, SSIM, correlation along with compression performance are discussed. The scheme maintains original image resolution while decreasing bit-rate for the blocks.