Privacy-preserving enhanced ring signature with Paillier based on batch verification for secure e-bidding

Blockchain is a promising technology that allows transactions to access the data in a decentralized and secure environment among participants on the open ledger network. Each bidder can access the copy of data in the blockchain network. On-chain data privacy for the permissionless blockchain e-bidding systems is the major issue of ensuring bid confidentiality, and bidder anonymity and privacy-preserving verification remains open challenge. To address this issue, the proposed Privacy-Preserving Enhanced Ring signature with Paillier based on Batch Verification for secure E-bidding (ERSPBV) that integrates ring-signed bid submission with Paillier Homomorphic Encryption (PHE) and batch verification smart contract to realize secure bidding, anonymity, and fine-grained access control. Ring signature ensures unlikability and anonymity of bidders during bid submission providing strong bidder privacy, this ensure untrace ability but prevent double signing. PHE supports secure aggregation and computation on ciphertexts without revealing individual values. The auctioneer checks bidder authorization using bidder authentication smart contract. Only those registered and permitted bidders to participate in the auction. Batch verification allows the auctioneer to verify multiple signatures submitted by multiple bidders at once to reduce total verification time. The bidders and auctioneer are interacting with each other through the smart contracts to achieve privacy and fairness and tamper-resistance. Emulated the cryptographic primitives and smart contract of this proposed e-bidding scheme on the Ethereum platform and the performance evaluation shows that high computational efficiency and secure bid processing is feasible in the Sepolia test network.