There is growing interest in Secure Collaborative Analytics, but fully oblivious query execution in Secure Multi-Party Computation (MPC) settings is prohibitively expensive. Recent related works proposed different approaches to trimming the size of intermediate results between oblivious query operators, resulting in significant speedups at the cost of some controlled information leakage. In Reflex, we generalize these ideas into a flexible and efficient trimming method for the output of the oblivious operators, that we call Resizer. Resizers can be seamlessly integrated between MPC-based query operators. This allows for precisely controlling the security/performance trade-off on a per-operator and per-query basis. Our method has the potential to accelerate the performance of current oblivious query execution by up to 200 times compared to fully oblivious query execution, and by approximately 7 times compared to existing approaches with the same security guarantees. Our work lays down the foundation for a future MPC query planner that can pick different performance and security targets when composing physical plans. This demonstration showcases the benefits of Reflex. More precisely, it focuses on the integration of our proposed resizers into the oblivious query plan, significantly enhancing performance. Conference attendees will have the opportunity to observe the efficient trimming of intermediate results and, additionally, they will be able to configure the oblivious execution settings, ranging from fully oblivious to fully revealed. This hands-on experience will highlight the benefits of our proposal in various obliviousness scenarios.
Gu et al. (Fri,) studied this question.