Bidder-anonymous English auction protocol based on revocable ring signature

Privacy has become a factor of increasing importance in auction design. This paper introduces an efficient and spontaneous privacy-preserving English auction protocol based on revocable ring signature. The proposed protocol has three appealing characteristic: first, it offers conditional privacy-preservation: while the auctioneer can verify that a bidder is an authorized participant in the system only the collaboration of auctioneer and registration manager can reveal the true identity of a malicious bidder. Second, it is one-time registration: the bidder can take part in plural auctions in one time registration. Third, it is spontaneous: the bidder can bid without interaction with the auctioneer and other bidders. Finally, it is efficient: it saves the communication round complexity comparing with previously proposed solutions.