(CLOUD 2024) Fast and Accurate Query Scheme over Encrypted Numerical Data in Cloud Environment

The query issue on outsourced encrypted data in cloud servers is a hot research topic in both the business and academic communities. Due to the high efficiency of Bloom filter in determining whether an element belongs to a set, the Bloom filter technique is often used as a fundamental component for constructing efficient query schemes. However, since Bloom filter may produce false positives with a certain probability, query schemes constructed based on Bloom filter may produce false positives in their query results with a certain probability. This paper combines prefix encoding, bilinear group operation and Bloom filter to construct a fast and accurate query scheme. Firstly, we construct a tree index, in which each node is associated with a range. We employ prefix encoding to process these ranges, then utilize Bloom filter to handle all the prefix codes of the ranges, and simultaneously employ bilinear group operation to process these prefix codes. The adoption of Bloom filter enables efficient data querying, while the adoption of bilinear group operation avoids the occurrence of false positive errors in the query results. Thus, our scheme can simultaneously support efficient and accurate query.