Multicast-based applications demand scalable security solutions for group communication infrastructure. Secure key distribution is one such solution that must be addressed in secure multicast sessions. In this paper, we present our approach named ESKD, is a novel solution to the hierarchical key distribution problem of large one-to-many group communication. ESKD is efficiently designed to achieve scalable and secure dynamic group membership. In ESKD, the intermediate nodes are not trusted and used as relaying nodes to assist in enforcing the secure multicast group without having any access to the multicast data. It combines the public and secret key systems in order to achieve both the speed advantages of secret key cryptosystems and security advantages of public key cryptosystems. ESKD guarantees group key security and group data secrecy. We also provide a comparative analysis of our approach with DEP [1] and show the efficiency of ESKD over DEP.