Multimedia Broadcast Multicast Services (MBMS) is a point-to-multipoint interface specification for
existing and upcoming 3GPP cellular networks, which is designed to provide efficient delivery of broadcast
and multicast services, within a cell or within the core network. Target applications include mobile TV and
radio broadcasting, file delivery and emergency alerts.The main goal of this paper is to assess the
performance of the Secure Multicast Overlay (SMO) and the Group Security Association (GSA). We
functionally compare GSA with SMO, in terms of Keys management procedures and look up policies
showing that GSA solution is appropriate in certain circumstances and SMO solution is appropriate in
others. The comparison will be for different parameters and different services. Also the computational cost
and storage cost for Logical Key Hierarchy (LKH) tree with and without dynamic rekeying will be
calculated.