A New Framework for Encryption and Authentication of Multimedia Data

The multiple Huffman table (MHT) based encryption technique for multimedia encryption gained much popularity, due to its simplicity, less complexity and good compression performance. At the same time, it is proved that the MHT based encryption system is vulnerable to several types of attacks. In this paper, the security issues of the MHT based encryption system are analyzed. On the basis of analysis, the paper proposes a modified version of MHT based encryption system, with minimal impact on its simplicity and compression performance. It is proposed to perform blockwise shuffling of the transformed image (in DCT domain) based on a chaotic map prior to the MHT stage, so that an attacker cannot retrieve the key because of the changes in the spatial arrangement caused by the blockwise shuffling in the transform domain. Moreover, to ensure copyright protection as well as traitor tracing, it is proposed to incorporate joint fingerprinting and decryption (JFD) technique at the receiver stage. The system is subjected to the known forms of attacks and it has been proved that the proposed system is able to resist the same with minimal level of increase in the system complexity.