Secure and Efficient Group Key Agreement Protocols



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Texas Tech University


Group communication is exploding in internet applications such as videoconferences, online chatting programs, games, and gambling. Current group communication protocols use a self-signed certificate which has a well-known weakness arising from the fact that members cannot ensure that the name on the public key is really a true member¡¯s name. Since members enter their own information there is no way to definitely prove that the information on the certificate is true or false. For secure group communication, secure member authentication and the integrity of messages must be provided among group members. To maintain secure member authentication, all group members must use a certificate which is issued by a certificate authority. This work focuses on developing secure member authentication and an efficient group key generation process. A MAC (Media Access Control) address-based authentication is proposed to compensate for the weakness of self-signed certificate-based authentication. The proposed approach supports member authentication by focusing on where a member is in addition to who a member is. After establishing secure member authentication a group key is generated for the integrity of messages. All group key generation protocols require all members to generate a common group key. In distributed computing environments membership is heterogeneous because members can work at laptops, mobile computers or workstations. If a low performance member using a mobile computer joins the group communication, then other members must wait until new member has finished generating the group key. As a result, the overall group key generating performance is always determined by the lowest performance member. Therefore, to ensure efficiency of the group key process, new protocols are proposed such that low performance members are systematically filtered out in order to avoid unnecessary delays.