A Zero-Knowledge Proof-Based Protocol for Privacy-Preserving Transactions on Public Blockchains

A Zero-Knowledge Proof-Based Protocol for Privacy-Preserving Transactions on Public Blockchains

연구 분야: Infrastructure

학회: BSCI '25: Proceedings of the 7th ACM International Symposium on Blockchain and Secure Critical Infrastructure

Public blockchains offer transparency and decentralization but also expose sensitive transaction data that compromise user privacy. This issue can be considered as a data breach if traditional financial systems attempt to migrate their infrastructures onto a public blockchain, creating a legal barrier to blockchain adoption in practical fields. Existing solutions often require restructuring the blockchain architecture, relying on protocols with high communication and computation costs, or launching a separate blockchain network, which can erode efficiency and undermine the decentralization of blockchain. In this paper, we propose a protocol that allows users to carry out privacy-preserving transactions on public blockchains. Our protocol leverages homomorphic encryption to encrypt user balances and employs commitment scheme to store the entire ledger on-chain compactly and efficiently. By integrating succinct zero-knowledge proofs, we enable the verification of state transitions (such as deposits, withdrawals, and fund transfers) without disclosing confidential inputs such as private keys, senders, receivers, or transaction amounts. We also present a concrete construction by selecting specific cryptographic primitives and analyze its security to demonstrate privacy and correctness. Finally, we conduct experiments on the proposed construction, measuring its performance to show that it can achieve both efficiency and scalability on an EVM-based blockchain.