Scalable Protection Scheme For The H.264/Svc Video Streaming

The newly standardized H.264/SVC enables multimedia suppliers to provide video bitstream with temporal, spatial and quality scalabilities to meet various needs of end users. Its bitstream scalability characteristic is also especially suitable for multimedia applications under merged heterogeneous networks with different network protocols, capacities and throughputs. The issue of content protection for the H.264/SVC has aroused researchers interests in recent years. In this paper, we present an efficient bitstream-oriented protection scheme for the H.264/SVC in a compression friendly and format compliant manner. The encryption is implemented at the Network Abstraction Layer (NAL) unit level. To improve the computational efficiency as well as to provide sufficient security, selective cryptographic algorithms with different computation cost are employed for different content level of SVC according to its significance. The I slice NAL units from the base layer of SVC bitstream are encrypted with the symmetric AES algorithm in Cipher Block Chaining (CBC) mode. And the other NAL units are protected by simplified XOR cipher. Furthermore, a robust key management (key generation and distribution) mechanism is also discussed in this paper. The security analysis and simulation results further verify that the proposed methods can effectively protect the H.264/SVC bitstream at low computational cost.