Secure group communication is an increasingly popular research area having received much attention in recent years. However, most existing approaches construct the group key without caring about the type of the group itself and the environment in which it evolves. This leads to inefficient solutions for real multicast groups. In this paper, we propose a new approach to enhance key management performance. In our solution, we take into consideration group characteristics. We first classify the various group characteristics and point out their influence on the efficiency of key management protocols. We, then, propose two key management protocols, which maintain good performance by adapting the key management process to the type of the group. A comparative study and simulation results evaluate the efficiency of our approach