A joint watermarking and encryption scheme for DCT based codecs

In this paper, a novel Joint Watermarking and Encryption scheme is presented. The design of proposed joint watermarking and encryption scheme involves the development of the encryption and watermarking schemes such that both the techniques are compliant with each other. Based on statistical analysis of continuous-tone still images, media data, in DCT domain, is partitioned into two parts. The encryption scheme exploits the energy distribution of AC component and DC bitplanes, and is carried out by encrypting those AC coefficients and selected DC component´s bitplanes. For the purpose of watermarking, a DC component based watermarking scheme that is presented in [1] is adopted. Additionally, as majority of the data is transmitted in compressed form thus the proposed scheme is compliant with image/video compression standards (i.e. JPEG, MPEG 2 and MPEG 4 / H.264). In last, the performance of the joint scheme is evaluated in terms of security analysis.