Research On Identity-Based Conference Key Establishment Protocol

With the rapid development of network technology, a variety of new applications based on group communication come forth constantly. When a group of people want to communicate securely over an open network, they need a common conference key to encrypt their communication information, in order to prevent unauthorized users from getting any useful information about authorized services. The establishment of conference key is the key for secure communication over an insecure channel. With the development of new applications based on group communication, research on conference key plays an important role not only in theory of cryptography and information security, but also in promoting the development of communication network and new electronic applications.This paper studied the existing protocols of conference key establishment, and proposed two improved conference key establishment protocols. The main work and innovation of this paper include:At first, this paper proposed a new anonymous conference key distribution protocol with the forward secrecy of conference key distribution center. Under the Gap Diffie-Hellman assumption, the identities of conference participants are anonymous to each other, and even anonymous to unattended ones. Furthermore, the proposed protocol is secure against impersonation and conspiracy attacks.Secondly, this paper presented a new fault-tolerant conference key agreement protocol based on the identity-based signature scheme given by Cha and Cheon. Under the Gap Diffie-Hellman assumption, honest participants can agree on a common conference key no matter how many participants are malicious, and passive adversaries get no information about the conference key established by honest participants. Furthermore, the protocol is efficient compared with the existing fault-tolerant conference key agreement protocol.