Top-k Query Processing on Encrypted Databases with Strong Security Guarantees

TL;DR

This paper introduces a novel, secure, and efficient method for processing top-k queries over encrypted cloud databases, ensuring strong security guarantees and practical performance.

Contribution

It presents the first provably secure top-k query protocol over encrypted data with optimized algorithms and an innovative encrypted data structure, EHL.

Findings

Protocol is secure under adaptive CQA security

Achieves significant improvements in space and time efficiency

Demonstrates practicality through experiments on real datasets

Abstract

Privacy concerns in outsourced cloud databases have become more and more important recently and many efficient and scalable query processing methods over encrypted data have been proposed. However, there is very limited work on how to securely process top-k ranking queries over encrypted databases in the cloud. In this paper, we focus exactly on this problem: secure and efficient processing of top-k queries over outsourced databases. In particular, we propose the first efficient and provable secure top-k query processing construction that achieves adaptively CQA security. We develop an encrypted data structure called EHL and describe several secure sub-protocols under our security model to answer top-k queries. Furthermore, we optimize our query algorithms for both space and time efficiency. Finally, in the experiments, we empirically analyze our protocol using real world datasets and demonstrate that our construction is efficient and practical.