Eisdspa: An Efficient and Secure Blockchain-Based Donation Scheme With Privacy Protection and Auditability

Charity donations are a critical mechanism for social resource distribution. However, traditional donation systems, typically centralized, are prone to issues such as data redundancy, vulnerability to single-point failures, and a deficiency in transparency and traceability. Although blockchain-based donation programs have emerged to address trust issues inherent in centralized models, they often neglect critical security concerns like privacy protection and identity authentication. This paper introduces Eisdspa, a blockchain-based donation system designed to offer identity authentication, auditability, and privacy protection. Specifically, we introduce an identity credential system that facilitates anonymous donations, shielding the identities of both donors and donees through the use of BBS+ signatures and zero-knowledge proofs of knowledge (ZKPoKs). Additionally, we ensure the integrity of goods donations by offering robust auditability and protecting user privacy with Pedersen commitments and ZKPoKs. We formally define the privacy aspects of Eisdspa and conduct a security analysis of the system under the random oracle model. A prototype implementation of the scheme, along with a comparative analysis with existing solutions, highlights the benefits of Eisdspa. Moreover, we assess the computational efficiency of Eisdspa, with experimental results indicating its high performance in computational overhead.