Anonymous Fair Auction on Blockchain

Online auction systems allow to achieve an optimal trading of digital goods and services in a competitive market. Existing blockchain-based auctions allow the bidders to take part in the process while maintaining the confidentiality of their bids in a decentralized, transparent, secure and auditable way. However, in a competitive market, parties would prefer not to disclose their interests to competitors, and to remain anonymous during auctions. In this paper, we firstly analyze the specific requirements for blockchain-based anonymous fair auctions. We propose a formal model tailored to study auction systems facilitating anonymity, and we put forward a generic protocol relying on existing cryptographic primitives, such as designated verifier ring signature, to achieve bid confidentiality and bidder anonymity. Finally, we prove it to be secure against the security model we defined.