Layered Encryption for Scalable Video Coding

A layered selective encryption scheme for scalable video coding (SVC) is proposed in this paper. The main feature of this scheme is making use of the characteristics of SVC. This method fully meets the encryption requirements of SVC and the encryption procedures are carried out at the network abstractor layer (NAL) level. Based on the different structure and importance of base tier and enhancement tiers, different domains are encrypted. For base tier, intra-prediction mode (IPM) and residual sign are selected. For enhancement tiers, temporal scalability and spatial/SNR scalability are distinguished. Furthermore, key generation and distribution schemes are presented. Stream cipher-Leak Extraction (LEX) algorithm is adopted to reduce computational cost. Experiments were performed to verify the proposed method using the joint scalable video model (JSVM), and the experimental results show that the proposed method protects the SVC streams effectively and supports full scalability; meanwhile, it can guarantee the robustness to transmission errors.