A quality-controllable encryption for H.264/AVC video coding

During the boosting of networking multimedia applications in recent years, secure transmission of video streams becomes highly demanded by many hot applications, such as confidential video conference and pay-TV. In this paper, we present a quality-controllable encryption method for H.264 coded video streams. Our goal has been to provide an efficient way to scramble the video streams to prevent illegal users from plagiarizing. By making use of the property of H.264 specification that Intra coded blocks are divided into three different types with different sizes, our algorithm provides the flexibility of scrambling the video up to certain level, which may be manually specified by the user or automatically determined by the system according to the networking traffic condition. Our design ensures that even the deepest scrambling level adds trivial performance overhead to the standard H.264 encoding/decoding process.