• Journal of KIISE:Computer Systems and Theory
• /
• v.32 no.10
• /
• pp.499-506
• /
• 2005

The growth of networks increase the importance of electronic commerces. Since the fair exchange protocol is an important part of electronic commerces, a number of researches have been done in relation to the fair exchange protocol. As the contract signing protocol is a part of fair exchange protocol, many protocols have been proposed, but most of them were focused on two-party protocol. Only a few were on the multi-party contract signing protocol. So far the optimistic multi-party contract signing protocol presented by Baum-Waidner has the least number of rounds in asynchronous network[4]. But, the lower bound on the number of rounds required by any optimistic multi-party contract signing protocol has been not known. In this paper, we present a tight lower bound on the number of rounds for optimistic multi-party contract signing protocol.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04a
• /
• pp.385-387
• /
• 2004

다자간의 계약서 서명 프로토콜은 Asokan등[1]에 의하여 제안되었다. 비동기 네트워크에서 다자간의 계약서 서명 프로토콜은 동기 네트워크에 비하여 효율성이 떨어져 그에 대한 연구가 많이 이루어졌다[2, 3, 4]. 지금까지 알려진 비동기 환경에서 가장 효율적인 다자간의 계약서 서명 프로토콜은 Waidner[4]에 의하여 제시되었다. 본 논문에서는 Waidner[4]가 제시한 프로토콜을 기본으로 하여 라운드 수를 줄인 프로토콜을 제시한다.