Review on Secret Data Hiding in Encrypted Compressed Video Bit Streams

To protect videos during transmission or cloud storage, encryption of compressed video bit streams and hiding privacy information can be done. Digital video sometimes needs to be stored and processed in an encrypted format to maintain security and privacy. It is also for the purpose of content notation and tampering detection. Here, data hiding directly in the encrypted version of H.264/AVC video stream .It has following three parts, H.264/AVC video encryption, data embedding, and data extraction. In H.264/AVC codec, the code words of intra prediction modes, motion vector differences, and residual coefficients are encrypted with stream ciphers. A data hider may embed additional data in the encrypted domain by using bits replacement technique, without knowing the original video content. Chaos crypto system is used here to encrypt/decrypt secret text data