Research On Compressed Video Secure Method

For the increasingly serious issues of video data content security and the current video featuressuch as easy to copy, easy to modify with the data, through the analysis of video encryptiontechnology and the watermark technology in recent years, combined H.264/AVC video compressioncharacteristics, the paper proposes three video content protection algorithms, which are securitylevel division encryption algorithm based on ISP, selective algorithm based on the entropy codingCAVLC and the protection algorithm combined digital watermarking and digital encryption. Thefirst and second algorithm use Advanced Encryption Standard(AES) cipher feedback(CFB) modeencrypt video data, the advantage of which is simple and fast operation, is a stream cipheralgorithm.The first algorithm encrypts the bit streams of the I frame, picture parameter set(PPS) andsequence parameter set(SPS). In order to meet the operability of the encrypted data, this paper studythe syntax elements of PPS and SPS, only encrypt part of the syntax elements. For different videoapplications demand different levels of security, select a certain number of macro-blocks in themacroblock level for selective encryption, gets security level division encryption algorithm. Finally,we analyze the effective confidentiality, real-time, compression rate of this algorithm.Experimental results show that our algorithm meet video content security, the real-time, andreduces the amount of encrypted data.The second algorithm encrypts video data based on the entropy coding CAVLC, only encryptsthe magnitude of the nonzero coefficients except tailing coefficient and tailing coefficient symbols.In order to reduce the amount of the encrypted data, the paper introduces video qualitydetermination threshold value, when the mass of the macro-block greater than the threshold value isnecessary to encrypt, or need not be encrypted, and that the judgment process is intelligent, videoquality is represented by peak signal to noise ratio PSNR. The experimental results show that thealgorithm reach the video content safety requirements, meet the real-time, reduce the amount ofencrypted data.The third algorithm combines watermark technology and encryption technology to protectvideo security. Taking into account when the video is decrypted by video provider who can notprove the copyright of this video, the paper introduces watermarking technology to solve thisproblem. The watermarking algorithm based on DCT transform coefficients embed watermark information generated. the key K,is public key Kp the private key Ks by video provider, bits of Kare used to select AC coefficients to embed watermark. The encryption algorithm is designed byusing watermark technology, according to the revelation of previous AC coefficient set scramblingencryption algorithm, in order not to change the compression bit rate, select the bit stream of ACcoefficients by key K to be modified. Experimental results show that each macroblock of the Iframe are embedded in more than1bit of the watermark information in this watermarkalgorithm,which has the good robustness and no change in the visual video quality, play the role ofa protection of the copyright of video; encryption algorithm meets cryptographic protocol designrequirements and has high security. The experimental results also prove that this algorithm meetsthe requirements of the various performance indicators.