Privacy-preserving comparable encryption scheme in cloud computing

Abstract

Data owners encrypt and outsource large size of data to cloud servers to reduce storage and management overhead. In traditional database, it is difficult for users to make comparable queries over ciphertexts. A Short Comparable Encryption (SCE) scheme has been emerged as a fundamental solution to enable data owners to conduct comparable queries over encrypted data. Unfortunately, it infers high computational and storage overhead as well as economic burden. In this paper, we first propose a basic Short Comparable Encryption scheme based on Sliding Window method, namely SCESW, which can relief computational and storage burden as well as enhance work efficiency by utilizing sliding window method. However, since the cloud server is always provided by semi-trusted third-party, auditing technology can be applied to protect data integrity. To this end, we improve SCESW scheme to present an enhanced auditing of SCESW scheme called PA-SCESW. Formal security analysis proves that PA-SCESW and SCESW schemes can guarantee data security, integrity as well as weak indistinguishability in standard model. Actual performance evaluation shows PA-SCESW scheme’s feasibility and efficiency in practice applications, especially for users with constrained computing resources and capacities.