ClaimGuard: A Blockchain-Backed Access Control Gateway for Privacy-Preservation in Auto-Insurance Claims

Abstract

Modern auto-insurance workflows require sharing heterogeneous digital evidence across multiple organizations. Yet, current cloud-based role-based access control mechanisms remain coarse-grained and poorly suited for expressing time, purpose, and case-specific constraints. This study presents ClaimGuard, which addresses these limitations by placing a blockchainbacked attribute-based access control gateway in front of existing evidence stores, enforcing fine-grained on-chain policies, and issuing short-lived capability tokens for authorized access. Implemented as a REST gateway with PureChain smart contracts, ClaimGuard is evaluated using realistic workloads involving up to 200 subjects and 1000 evidence resources. Experiments on a local Ethereum network shows sub$\sim 70 ~\text{ms}$tail latency, throughput exceeding$\sim 1000$requests/s, rapid policy updates, and zero false accepts, demonstrating the practicality of decentralized, auditable access control for privacy-preserving claims evidence sharing.