SecBerg: Secure and Practical Iceberg Queries in Cloud

Secure queries are fundamental to data security, particularly in cloud databases. In data analytics, one of the common and practical queries is the iceberg query that can find aggregate values above a specified threshold. However, existing secure aggregate query schemes: 1) are unable to support secure iceberg queries equipped with the HAVING clause; 2) only consider additive aggregate functions; and 3) suffer from performance issues due to the use of homomorphic encryption to encrypt databases. In this article, we present a secure iceberg query scheme, SecBerg, to support both addition-based and comparison-based aggregate functions and ensure high efficiency and security simultaneously. To make it possible, we propose a secure bitmap index system to encode database values and pioneer the use of the arithmetic secret sharing technique to protect databases in the cloud environment. Furthermore, we carefully design efficient and secure protocols over arithmetic secret sharing to construct our SecBerg. Extensive evaluations are conducted, and the results indicate that SecBerg is significantly more efficient than the state-of-the-art relevant scheme in computational overhead and can attain orders of magnitude performance improvement at best.