A sealed-bid electronic marketplace bidding auction protocol by using ring signature

We modified the multi-agent negotiation test-bed auction scheme which was proposed by Collins et al. In 2004, Jaiswal et al. have modified Collins's scheme, but Jaiswal's scheme still has some security weaknesses: such as replay data attack and DOS (denial-of-service) attack, collision between customers and a certain supplier. So the proposed protocol tries to reduce DOS attack and avoid replay data attack by using improved ring signature scheme, also it achieves perfect anonymity. And it publishes an interpolating polynomial for sharing the determination process data and avoids collusion between a customer and a certain supplier. Furthermore, the proposed scheme relaxes the trust assumptions for three-party in Jaiswal's scheme. According to comparison and analysis with other protocols, our proposed protocol shows good security