The emergence of cloud computing has enabled users to store and manage data at a low cost and high availability, which made outsourcing data become appealing to its customers. Since the inception of cloud computing, efforts have been dedicated to improve the security and performance of cloudbased backup services. However, there is yet to be implemented a complete scheme that provides security, utility, and performance. Existing schemes focus on one aspect of the backup service; security of data, functionality of the scheme (e.g. searching data for a keyword), or performance. In this paper, we introduce a cloud backup system aiming to balance all three aspects of the service. The scheme utilizes encryption intensity selection, which allows users to select the encryption intensity of their files, secure deduplication, and querying on encrypted data. The performance of our cloud backup system is measured over an OpenStack cloud installed on CloudLab resources. Results demonstrate that our scheme can improve backup service security and performance while providing more functionality of the encrypted data