A Lightweight Polynomial–Based Provable Data Possession Scheme With Blockchain for Integrity and Ownership Verification

Data outsourcing improves the scalability of large‐scale storage systems but introduces risks related to data tampering and unverifiable ownership claims. Existing provable data possession (PDP) schemes often incur substantial cryptographic overhead and primarily focus on data integrity. This paper proposes a lightweight PDP scheme that uses a user‐specific polynomial to construct integrity tags without bilinear pairing operations. The scheme is integrated with a blockchain smart contract to provide dual verification: The file owner verifies outsourced data integrity, while the smart contract validates ownership proofs, challenge freshness, file versions, and record validity on behalf of the external server. Experimental results identify π _d = 3 and Q = 60 as practical parameter settings. The implemented protocol completes recurring setup, ownership registration, and ownership verification in 465.95, 27.47, and 54.33 ms, respectively. Under a common primitive operation model, the proposed scheme achieves the lowest tag generation cost and a lower integrity audit cost than five of the six compared schemes. The results demonstrate efficient and scalable integrity and ownership verification for outsourced storage systems.