Chaos Based Partial Encryption of SPIHT Compressed Images

Resource-constrained wireless IP networks require compression based encryption techniques for secure archival, transmission and distribution of multimedia data. A partial encryption technique based on SPIHT encoder is thus proposed that provides enhanced security level by encrypting selected bit values and keeping the encrypted bit locations as secret. The proposed technique preserves the scalability property of the encoder and provides high data security without adversely affecting the compression efficiency. Two new edge based parameters, edge ratio and edge differential ratio are also proposed to measure the degradation in the encrypted image. Thorough performance and security analysis as regards to various evaluation metrics ascertains its high performance and ability to withstand cryptanalytic attacks.