    @inproceedings {JianyingZhou2006,
	title = {A Synchronous Multi-Party Contract Signing Protocol Improving Lower Bound of Steps},
	booktitle = {21st International Information Security Conference (IFIP SEC{\textquoteright}06)},
	series = {LNCS},
	number = {201},
	year = {2006},
	month = {May},
	pages = {221-232},
	publisher = {Springer},
	organization = {Springer},
	abstract = {<p>Contract signing is a fundamental service in doing business. The Internet has facilitated the electronic commerce, and it is necessary to find appropriate mechanisms for contract signing in the digital world. A number of two-party contract signing protocols have been proposed with various features. Nevertheless, in some applications, a contract may need to be signed by multiple parties. Less research has been done on multi-party contract signing. In this paper, we propose a new synchronous multi-party contract signing protocol that, with n parties, it reaches a lower bound of 3(n \&minus; 1) steps in the all-honest case and 4n \&minus; 2 steps in the worst case (i.e., all parties contact the trusted third party). This is so far the most efficient synchronous multi-party contract signing protocol in terms of the number of messages required. We further consider the additional features like timeliness and abuse-freeness in the improved version.</p>},
	author = {Jianying Zhou and Jose A. Onieva and Javier Lopez}
}
