Digital image security improvement by integrating watermarking and encryption technique

This paper proposed an algorithm to improve image security and its authority for its owner. This has been achieved by means of watermarking and encryption technique. Two methods RC4 and Advances Encryption Standard (AES) are adopted for encryption which uses stream cipher and block cipher respectively. For getting the watermarked image Rational Dither Modulation (RDM) method is used. First step of the algorithm is to embed the watermark and then the watermarked image is encrypted using secret key of the encryption technique. We have used blind watermark extraction technique for extraction of the watermark. Performance of the watermarking and encryption techniques is investigated for robustness, perceptual quality and security of the proposed algorithm.