Multi-factor User Authentication on Group Communication

Group communications are becoming popular by explosively increased Internet usage, and there are various group communications on Internet applications such as video conferences, on-line text chatting programs, online games and gambling. However, the conventional group key agreement protocols are only focused on how to minimize the computational overhead by concentrating on generating the common group key efficiently. As a result, the common group key is generated efficiently. However, a failure in user authentication permits unknown attackers to obtain valuable information during the group communication. This paper proposes a Media Access Control (MAC)-based authentication in the group key agreement in order to secure the user authentication process in group communications. Without a preliminary agreement, participants in a group communication cannot trust each other in the beginning of the group setup. Therefore, the group controller, who is randomly selected from the group members, needs a security deposit from all members in case an illegitimate user tries to join the group. The user MAC address proposed in this paper can act as a security deposit to provide a secure communication channel while preventing the MAC spoofing problem.