MSCPR: A maintainable vector commitment-based stateless cryptocurrency system with privacy preservation and regulatory compliance

Abstract

In traditional account-based cryptocurrency systems, maintaining the state of all accounts consumes significant storage space. To reduce storage costs, recently some studies propose to leverage vector commitment schemes to design stateless cryptocurrency systems. In such systems, validators only need to store a commitment to the state vector to validate transactions. However, to prove membership in the state vector, each user is required to locally maintain a position proof. This introduces a burden as users need to update their proofs every time the commitment value changes. Additionally, existing stateless systems often include users’ account balances and transferred values in transactions explicitly, which compromises privacy. To address above issues, we propose a stateless cryptocurrency system based on a maintainable vector commitment scheme. In the proposed system, a bucketing technique is employed to simplify the proof update operations. And we leverage the homomorphic property of vector commitments to preserve the confidentiality of transactions. Furthermore, by constructing an anonymity set, transaction anonymity is ensured. To prevent adversaries from taking advantage of the anonymity, we design a predicate encryption-based regulation scheme. Through a series of simulations, we demonstrate that the proposed system is storage-efficient, with acceptable time overhead for privacy preservation and regulatory compliance.