Practical volume-hiding range searchable symmetric encryption using trusted execution

Searchable symmetric encryption (SSE) enables clients to securely outsource private data to cloud servers while preserving search functionality. Addressing the increasing demand for range queries, which involve matching documents to fields with a range of keywords, remains a challenge. Existing volume-hiding range query schemes fail to address volume pattern leakage during the document fetch phase and lack support for dynamic operations such as addition and deletion of documents. To overcome these limitations, we propose EDVHRQ, an efficient, dynamic, and volume-hiding range query scheme enabled by Intel SGX. Our scheme introduces novel strategies: (1) packetization, which conceals response sizes while minimizing server storage and communication costs, and (2) the optimal best range cover (OBRC) method, which transforms query ranges into a minimal set of trapdoors to accelerate range queries. Unlike existing solutions, EDVHRQ achieves a single roundtrip query process between the client and the cloud server. We formally analyze the security guarantees of EDVHRQ, demonstrating its robustness against volume pattern leakage. Experimental evaluations highlight its superior performance, achieving up to 18.8$\times$ and 56.5$\times$ faster query execution compared to HybrIDX and SEAL, respectively, while significantly reducing server storage costs.