# SBIBD 네트워크에서 다자간 원격회의를 위한 회의용 키 생성 프로토콜

• 김성열 (울산과학대학 컴퓨터정보학부) ;
• 김동현 (순천청암대 부동산학과)
• Accepted : 2009.11.20
• Published : 2009.12.31

#### Abstract

A conference key agreement system is a scheme to generate a session 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 protocol 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 modified Diffe-Helman form of ${\prod}_{i=0}^{v-1}R_i$, where v 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 $O(v{\sqrt{v}})$. Our protocol can be proved as computationally difficult to calculate as discrete logarithms.

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