An efficient hierarchical key management of H.264/scalable video coding

This paper proposes a novel scheme to efficiently manage multi-keys used for layered access control of H.264/scalable video coding. The approach is to transform this problem into hierarchical encryption, by accomplishing with cryptographic hash function and two-dimensional key derivation. The efficiency of the proposed scheme is summarized in the following three points. 1) It is secure to prevent various types of attackers. 2) It is flexible to update keys for adding/deleting a layer or a user. 3) It costs little storage for both key server and users to keep keys.