The purpose of key management is to provide secure procedures for handling cryptographic keying material to be used in symmetric (or) asymmetric cryptographic mechanisms. Key management schemes generally depend on the type of keys to be handled, on the given facilities & on the specific application. Key management scheme focus on the reduction of transmission overhead caused by distribution of associated key material over broadcast and interact channel. In multicast it is important to update security keys when a user joins or leaves the multicast group. This paper is to reduce the number of keying messages & to update the key at a reduced cost.