An efficient public key video crypto-system with data hiding techniques

A new public key crypto-system for transmitting secured MPEG videos is proposed in this paper. Our proposed system retains the MPEG bit stream structure, but with the DC differential values and some AC coefficients of intra-coded macroblocks being encrypted, hence resulting in a content invisibility for all I-, P-, and B-frames. In this way, our algorithm is efficient in terms of processing speed and data conversion overhead. Parameters that control the generation of several pseudo-random binary patterns for encryption can be dynamically updated, encrypted by a public-key algorithm, and delivered to the receiver through the encrypted MPEG video by data embedding techniques. Since these parameters can be recovered for legal users by using a private key, transmission security can be thus achieved. Besides, our crypto-system is capable of changing these parameters dynamically and making them readable at the receiver side, it is difficult for illegal users to deduce the decryption parameters by some statistical methods.