A Linkable Anonymous and Verifiable Sealed-Bid Auction Scheme for Consortium Blockchain

Sealed-bid auctions require bidders to submit concealed bids within a prescribed bidding period, after which the bids are opened and compared to determine the highest bidder. However, existing auction systems still face challenges in protecting bidder privacy and bid data, verifying auction results, and reducing dependence on centralized auctioneers. This paper proposes LAV-Auction, a linkable anonymous and verifiable sealed-bid auction scheme for consortium blockchain. A registration authority publishes a ring of eligible public keys. Each bidder submits a commitment, a bid ciphertext containing the bid value and commitment randomness, and an auction-scoped linkable ring signature. The signature hides which registered key was used, while its key image enables the contract to reject repeated bids from the same credential in the same auction. After the contract fixes the accepted record order, the auction committee decrypts the bid ciphertexts. A verifier recomputes the digest of the frozen ledger records. It then verifies a Groth16 proof showing that the announced winner corresponds to a valid frozen bid with the highest value. LAV-Auction provides bidder anonymity, bid confidentiality before committee decryption, duplicate bid prevention, and verifiable winner correctness over the frozen valid bid set. Experiments on a Hyperledger Fabric implementation demonstrate practical computation, communication, and scalability trade-offs. The results show that LAV-Auction achieves millisecond-level result verification through succinct Groth16 proofs while maintaining compact result certification payloads under increasing bidder scales.