An access control model for video database systems

A novel approach for modeling access control in video databases is presented. The proposed access control mechanism uses both the semantics and the structural composition of video data. The unit of authorization, a video element, can either be a sequence of video frames or a video object that appears as part of a frame, e.g., the face of an anonymous person in an interview. The components of the access control model are the video elements, the potential users, and the mode of operation, e.g., viewing, or editing. Video elements are speci ed either explicitly by their identi ers or implicitly by their semantic con tents, while users are characterized b y the user credentials. An algorithm is presented that determines the authorized portions of a video that a giv en user may acquire, giv en the user's creden tials, the video content descriptions, and the type of requested video operations. The description of the implementation of a prototype MPEG-2 based video database system with access con trol are also presented.