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.