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.