MULTIMEDIA DATA ENCRYPTION IN BLOCK-BASED CODECS

摘要

Multimedia data encryption is suitable for copyright protection. In this paper, a multimedia encryption scheme combined with block-based codecs (such as JPEG/JPEG2000, MPEG1/2, or H.261/263) is proposed, which permutes block positions, permutes coefficients (discrete cosign transform (DCT) coefficients or wavelet coefficients), and encrypts coefficient signs. It is extended to a perceptual encryption scheme and a secure video-on-demand (VOD) scheme. Theoretical analyses and experimental results show that this encryption scheme is of low-cost, supports direct bit-rate control, and is of higher robustness to transmission errors. These properties make it suitable for secure image or video transmission.