关键词: 电子合同, 离散对数, 有序多重数字签名, 效率

Abstract: Electronic contract is an important protocol in today’s society for some users, which plays a vital role in the development and interest of business or personal, it becomes a main problem how to design a fair and efficient electronic contract signing protocol. In this paper, based on difficulty of discrete logarithm problem, using a special signature—sequential-multi digital signature， we design a fair and efficient electronic contract signing protocol. By increasing the time stamp, it solves the defect of signature delay, makes sure that signatures will be done in the certain order and time strictly. So it is more efficient. By proving and analyzing, the scheme is correct and feasible.

Key words: electronic contract, discrete logarithm, sequential-multi digital signature, efficiency