A Scalable Method for Access Control in Location-Based Broadcast Services

One important problem for such public broad-cast LBS is to enforce access control on a large number of subscribers. In such a system a user typically subscribes to a LBS for a time interval (a, b) and a spatial region (xbl, ybl, xtr, ytr) according to a 3-dimensional spatial-temporal authorization model. In this paper, the authors argue that current approaches to access control using group key management protocols are not scalable.