Selective Video Encryption Technology Research Based On H.264

With the rapid development of network technology, multimedia applications are becomingmore common, and the video is the most intuitive and vivid multimedia forms. Video transmissionin the open network is very vulnerable to illegal listening, replay, tampered attack, designingsecurity video encryption algorithm to protect video content is becoming very important. H.264isone of the most popular and widely used video coding standard, because some of the features ofvideo itself, the traditional video encryption algorithm based on the data encryption standard is lowefficiency, and relatively high efficiency based on the characteristic of video encryption algorithmis not enough safety, therefore, how to compromise between efficient video encryption andsecurity design is a new challenge in the study of video encryption algorithm. The full text mainlyresearch work including:(1) This paper puts forward a new encryption scheme based on frame prediction macroblockDCT coefficient layered, DCT encryption method is a kind of selective encryption scheme, in theencryption process, research focus on the transformation of the DCT coefficient, on the DCTcoefficient layered operation, important information will be more concentrated after thetransformation, more convenient cryptographic operations.(2) This paper puts forward a kind of video encryption algorithm based on human visualperception characteristics of motion attention. Based on video analysis technology has become ahot research topic in the field of multimedia analysis, and simulation of human cognitive processesis used to study the video encryption technology, video encryption based on visual perceptionmodel divides macroblock type, and then different macroblock type chooses different encryptionmethod. Effectively combining visual perception and video encryption make the choice of theencrypted data more reasonable.(3) Extracting key frames in the encode process, and combine with H.264entropy coding,puts forward a kind of entropy coding encryption algorithm based on key frame selection. Theapplication of key frames greatly reduce the amount of video encryption data, provides astreamlined organization to deal with video content. Key frame contains the most important videoinformation, extracts it based on motion vector method, encrypts the important frame in order toachieve the ultimate goal of the whole video encryption. This paper puts forward three selective encryption algorithms, but the methods of choiceimportant data are different. The first algorithm is concentrating the important data and then DCTcoefficient encryption, the second approach is based on macroblock to select the important data forthe unit, and the third method is based on the frame unit to select key information. Experimentalresults show that the proposed algorithms do not change the video encoding compatibility, onlyexpense a small coding time and get good visual effect, and use of the chaotic sequence in theencryption process, enhances the key space and security of the encryption scheme.