Model of an Encrypted Cloud Relational Database Supporting Complex Predicates in WHERE Clause

Even though the concept of a Database-as-a-Service (DaaS) is becoming more popular and offers significant expenditure cuts, enterprises are still reluctant to migrate their data storing and processing to the cloud. One of the reasons to that is a lack of solid security guarantees. Encrypted database is one of the major approaches to address the security of cloud data processing. However, in order to provide processing capabilities over encrypted data, multiple techniques need to be combined and adjusted to work together. This paper introduces a modular and extensible framework model of an encrypted database, which makes it possible to execute a wide range of queries, including those with complex arithmetic expressions, retaining data privacy even with an adversary gaining full access to the database server. Proposed model could be used as a basis for encrypted database systems with various functional requirements.