Efficient multimedia data encryption based on flexible QM coder

Efficient multimedia encryption algorithms are fundamental to multimedia data security because of the massive data size and the need of real-time processing. In this research, we present an efficient encryption scheme, called the RCI-QM coder, which achieves the objective of encryption with a regular QM coder by applying different coding conventions to encode individual symbols according to a statistically random sequence. One main advantage of our scheme is the negligible computation cost associated with encryption. We also demonstrate with cryptanalysis that the security level of our scheme is high enough to thwart most common attacks. The proposed RCI-QM coder is easy to implement in both software and hardware, while providing backward compatibility to the standard QM coder.