Separable authentication in encrypted HEVC video

A joint encryption and authentication scheme for HEVC compressed video is proposed in this work. It produces a HEVC format compliant video stream that permits the authentication process to be carried out irregardless of the video being in the encrypted or plaintext (i.e., decrypted) form. To achieve this separable property, one set of syntax elements within the HEVC standard is utilized to achieve authentication, while another set is exploited for encryption. Specifically, for authentication, information such as coding unit size in each video slice is utilized to generate the authentication code, which is then embedded into each video slice to detect the tampered regions. A two-level authentication method is implemented to facilitate the legitimacy verification process. On the other hand, for video encryption, syntax elements in the HEVC standard including Sign Bins, Transform Skip Bins and Suffix Bins are randomized to perceptually distort the video. Experiment results show that by using the proposed encryption modules, the perceptual quality of the plaintext video can be distorted, and the distorted video can be restored to the original HEVC compressed video. Furthermore, the proposed joint scheme is verified to be viable in detecting and localizing the tampered regions. Finally, a pragmatic comparison among the proposed and conventional joint schemes is performed.