Conference key agreement protocol with non-interactive fault-tolerance over broadcast network

摘要

Most conventional conference key agreement protocols have not been concerned with a practical situa_tion. There may exist some malicious conferees who attempt to block conference initiation for some purposes, e.g. com_mercial, political or military benefit. Instances where con_ference must be launched immediately due to emergency, efficient detection of malicious behavior would be needed. Recently, Tzeng (IEEE Trans. Comput. 51(4):373-379, 2002) proposed a fault-tolerant conference key agreement protocol to address the issue where a conference key can be established among conferees even though malicious confer_ees exist. However, his protocol might be complex and inef_ficient during fault-detection. In the case where a malicious conferee exists and a fault-tolerant mechanism is launched, complicated interactions between conferees will be required. In this paper, we introduce a novel strategy, where any mali_cious conferee may be identified and removed from the con_feree list without any interaction. With such a non-interactive fault-tolerance, conferences could be established and started efficiently. A complete example of our protocol will be given to describe the fascinating fault-tolerance. We analyse the security of our protocol regarding four aspects, i.e. correct_ness, fault-tolerance, active attack and passive attack. The comparisons of performance between our protocol and that of Tzeng are also shown. As a whole, the advantage of our protocol is superior to that of Tzeng under the situation where malicious conferees exist.