A Secure and Efficient Query Processing Algorithm Over Encrypted Database in Cloud Computing

Since studies on privacy-preserving database outsourcing have been spotlighted in a cloud computing, databases need to be encrypted before being outsourced to the cloud. Therefore, a couple of privacy-preserving kNN query processing techniques have been proposed over the encrypted database. However, the existing schemes are either insecure or inefficient. Therefore, in this paper we propose a secure and efficient kNN query processing algorithm. Our algorithm preserves both data privacy and query privacy while hiding data access patterns. To achieve a high efficiency in query processing, we also propose efficient and secure protocols using Yao’s garbled circuit and a data packing technique. Through our performance analysis, we verify that our proposed scheme outperforms the existing schemes in terms of a query processing cost.