Conference Key Agreement Protocol Employing a Symmetric Balanced Incomplete Block Design
김성열, 이옥빈, 최동민, 정일용 · 한국멀티미디어학회 학술발표논문집 · 2007
A conference key agreement system is a scheme to generate a conference key in a contributory manner in order to communicate with each other securely among participants. In this paper an efficient conference key agreement system is proposed by employing symmetric balanced incomplete block design(SBIBD), one class of block designs. The protoco1 presented not only minimizes the message overhead and message exchanging rounds but also makes every participant contribute evenly for generating a conference key. Our protocol constructs a conference key which takes the forms of II υ-1 i=0 R i , where υ is the number of participants and R i is a random number generated from member i. In a special class of SBIBD, it takes only 3 rounds message exchange and message overhead is O(υ√υ). Our protocol can be proved as computationally difficult to calculate as discrete logarithms.