Design and analysis of querying encrypted data in relational databases

Security and privacy concerns as well as legal considerations force many companies to encrypt the sensitive data in databases. However, storing the data in an encrypted format entails non-negligible performance penalties while processing queries. In this paper, we address several design issues related to querying encrypted data in relational databases. Based on our experiments, we propose new and efficient techniques to reduce the cost of cryptographic operations while processing different types of queries. Our techniques enable us not only to overlap the cryptographic operations with the IO latencies but also to reduce the number of block cipher operations with the help of selective decryption capabilities.