Abstract: This paper introduces a project-oriented blockchain-based reimbursement platform model for universities, aimed at addressing the trust deficiency and inefficiency issues inherent in the traditional financial reimbursement process. To accommodate the dynamic roles of participants in a multi-project environment, an attribute-based access control (ABAC) model is employed to facilitate fine-grained permission management. The traditional single-chain structure is insufficient for managing the complex logical relation-ships between projects and invoices. To overcome this limitation, a dual-chain storage structure, comprising a main chain and sub-chains, along with a corresponding logical transaction algorithm, is devised. This methodology effectively resolves the intricate correspondence between various reimbursement statuses and projects. Furthermore, a Merkle tree index table query algorithm (MTIT) is designed to enhance query efficiency. Experimental results demonstrate that the proposed design exhibits robust performance stability across various transaction volumes and meets the daily financial management requirements of universities.

Key words: university financial management, attribute-based access control (ABAC), dual-chain structure, Merkle tree index table