A DCT-based MPEG-2 transparent scrambling algorithm

Recently, several encryption algorithms have been proposed, which are applied to MPEG-2 video streams. These algorithms try to optimize the encryption process and improve encryption speed by exploiting the spatial and temporal properties of video retrieval and display process. As a new branch of encryption, transparent scrambling has its own merits and special prospects. A new transparent scrambling algorithm proposed in this paper performs an arbitrarily degraded view of decoded picture by encrypting in DCT domain. This technique is applicable to the broadcast systems such as DVB/ATSC, which use MPEG-2 as compression standard.