Privacy Preserving Range Query Search over Encrypted Numeric Data in Cloud

In cloud computing, to protect privacy when outsourcing database management systems, confidential data (e.g., bank account balance) has to be encrypted which however renders traditional query processing methods (e.g., the B-tree index) inapplicable. In this thesis, we consider processing range query search (e.g., retrieving all records with a bank account balance being less than some threshold) over a confidential numeric attribute with two main challenges. First, the confidentiality requires hiding the value and the relative order of the attribute in records from the cloud server, but computing a range query requires comparing the values of this attribute. Second, since the encrypted data does not preserve the closeness of plaintext values (for privacy reasons), a straightforward search has to scan the entire encrypted data to retrieve wanted records, which is not scalable for data of the cloud scale. In this work, we present a novel searchable encryption/index scheme to address these challenges.