Data Hiding in H.264/AVC Video Encryption with XOR-ed User Information and Data in File Format

Digital video sometimes needs to be stored and processed in an encrypted format to maintain security and privacy. In this paper, a novel scheme of data hiding directly in the encrypted version of H.264/AVC video stream is proposed, which includes the following three parts, i. e. , H.264/AVC video encryption, data embedding, and data extraction. By analyzing the property of H.264/AVC codec, the codewords of intraprediction modes, the codewords of motion vector differences, and the codewords of residual coefficients are encrypted with stream ciphers. Then, a data hider may embed additional data in the encrypted domain by using codeword substitution technique, without knowing the original video content. In order to adapt to different application scenarios, data extraction can be done either in the encrypted domain or in the decrypted domain. The enhanced feature added to the system is each user id can be saved inside the video, so that the uploader of the video can decide who all can access the data within the video.