A Secure Order-Preserving Encryption Scheme Based on Encrypted Index

With the development of cloud computing, data owners usually choose to store data in the cloud. But cloud servers may not be fully trusted. Due to privacy concerns, data owners need to encrypt the data before storing it in the cloud. There is still a lack of solutions that satisfy both safety and efficiency. To perform secure queries on encrypted data, we propose a scheme. The scheme includes an encrypted index based on B+ tree, which can hide the order information of sensitive data. It also includes a secure search algorithm based on the encrypted index, which is implemented through the interaction protocol between the client and the server. We analyze the scheme's security and prove that the scheme can protect the privacy of data, queries, results, and access patterns. At last, we perform experiments on five datasets to verify that the scheme is effective.