Hierarchical Video Encryption Schemes Based On H.264/SVC

With the development of network technologies and wider use of multimedia information, video data, which is accessible, easy to damage and attack during its storage and transmission, get more and more concerned in its security. Although traditional encryption technology and information security theory has been developed very well, video data encryption must consider its video data characteristics: a large quantity of data, special coding structure, high real-time requirements, diversity of application environment and application of scalable video coding technology. Traditional encryption technology cannot directly be applied to video coding in the, these video data characters put forward strict demands to video encryption algorithm. Not only having high security, do video encryption algorithms have fast working speed and keep efficiency of compression and coding format. Many existing video encryption schemes can't satisfy the requirements of video encryption completely. Video encryption algorithm based on the micro block features or combined with the process of entropy coding is considered very important to future research.In this paper, we introduced the research background,meaning and current situation of video encryption technology.The second, we analyzed and compared the arithmetic of encrypting video by the relative between coding process and encrypting process. Basing the different types of algorithm, we analyzed the safeness, real-time achievement, increasing data quantity, data format compability, data operability, application range and so on.Then, we described the scalable video coding SVC technology and introduced the layer prediction in detail. And based on H.264/SVC entropy coding, two video encryption schemes were proposed in this paper from the perspective of Macroblock and Coding Stream respectively.One encryption exists in the process of encoding macroblock to each macro block. Key information of each macroblock, such as DC coefficients, MVD variables is selected to be encrypted. This scheme has characteristics of security, moderate complexity, and real-time.The latter one encrypts CAVLC entropy coding of individual elements from the perspective of stream encryption. In this paper, we refer to the CAVLC entropy coding encryption schemes proposed by Li Xiaoju[1]. The experiments show the CAVLC entropy coding encryption scheme greatly enhances video encryption security, reducing unnecessary information encryption.The paper summarized and prospected at last. The research of this paper can be applied to the actual system and make a reference effort on video encryption based on entropy coding.