PIR-TEE: Powering Privacy and Performance for Lightweight Blockchain Clients

The rapid growth of blockchain networks has led to a surge in lightweight client adoption, as full nodes become increasingly resource-intensive. This shift introduces two critical challenges: 1) Lightweight clients must rely on external sources for transaction data, exposing users to potential privacy breaches and security threats. 2) Existing privacy-preserving query sys-tems struggle to handle the vast amounts of data in blockchain networks efficiently. To tackle the dual challenges of maintaining query privacy and managing extensive blockchain data efficiently, our framework seamlessly integrates state-of-the-art Private Information Retrieval (PIR) techniques with Trusted Execution Environment (TEE) hardware capabilities. Our solution also sup-ports diverse query types, including keyword-based, predicate, and range queries, while enabling lightweight clients to verify the integrity and completeness of query results. Experimental results demonstrate that our approach reduces full-node storage overhead by nearly 50 % and improves communication efficiency by 4x compared to state-of-the-art PIR-based solutions, with only a modest 4–11 % increase in query time for integrity verification.