Perceptual cryptography on wavelet-transform encoded videos

A perceptual cryptography on 3D-SPIHT compressed videos is proposed. By confusing different numbers of wavelet coefficients, encrypting different numbers of coefficients' signs and confusing the positions of different data cubes, videos can be degraded to different degrees under the control of a quality factor. Theoretical analyses and experimental results show that its encryption strength can be adjusted according to a certain quality factor, it is of low-cost, it supports direct bit-rate control, and it is not sensitive to transmission errors. These properties make it suitable for network multimedia applications with real-time operation requirement, such as video-on-demand (VOD) systems, multimedia communication, wireless or mobile multimedia, and so on.