Blockchain-enabled decentralized privacy-preserving group purchasing for retail energy plans
In traditional retail energy markets, group purchasing reliant on trusted third parties suffers from privacy leakage and insufficient transparency. This paper proposes a decentralized, privacy-preserving group purchasing mechanism that integrates Ethereum blockchain with secure multi-party computation (SMPC). Users collaboratively evaluate energy plans and jointly determine optimal supplier switching without revealing private consumption data. We design a publicly verifiable smart contract—implemented in Solidity—that ensures fraud resistance, fair cost allocation, and mutual compensation. Our approach establishes the first group-purchasing paradigm characterized by *no trusted third party*, *zero data leakage*, and *verifiable decision-making*. Empirical deployment demonstrates that the mechanism simultaneously preserves user privacy and significantly improves collective economic benefits and decision-making efficiency.