DuoCryptDB: A Privacy-Focused Two-Cloud Solution for Numeric SQL Range Queries

Enterprises and individuals commonly delegate the management of their databases to realize convenient and cost-effective applications and services. However, existing secure database schemes are susceptible to privacy breaches when deployed on cloud servers, as data owners lack jurisdiction over them. Particularly vulnerable are numerical range queries such as ">" or "<", which inadequately shield against privacy risks like statistical property leakage and access pattern inference. Moreover, the escalation in queries conducted exacerbates information leakage to the cloud server. To overcome these challenges, this study introduces a two-cloud architecture for secure databases, integrating intersection protocols to safeguard privacy in various numeric range queries. Security analysis demonstrates the robust protection of numerical information against cloud providers in our proposed scheme.