Cloud file systems offer organizations a scalable and reliable file storage solution. However, cloud file systems have become prime targets for adversaries, and traditional designs are not equipped to protect organizations against the myriad of attacks that may be initiated by a malicious cloud provider, co-tenant, or end-client. Recently proposed designs leveraging cryptographic techniques and trusted execution environments (TEEs) still force organizations to make undesirable trade-offs, consequently leading to either security, functional, or performance limitations. In this paper, we introduce TFS, a cloud file system that leverages the security capabilities provided by TEEs to bootstrap new security protocols that meet real-world security, functional, and performance requirements. Through extensive security and performance analyses, we show that TFS can ensure stronger security guarantees while still providing practical utility and performance w.r.t. state-of-the-art systems; compared to the widely-used NFS, TFS achieves up to 2.1X speedups across micro-benchmarks and incurs <1X overhead for most macro-benchmark workloads. TFS demonstrates that organizations need not sacrifice file system security to embrace the functional and performance advantages of outsourcing.

翻译：云文件系统为组织提供了可扩展且可靠的文件存储解决方案。然而，云文件系统已成为攻击者的主要目标，传统设计无法保护组织免受恶意云提供商、租户或终端客户端可能发起的多种攻击。近期提出的利用密码学技术和可信执行环境（TEE）的设计仍迫使组织做出不利的权衡，从而导致安全、功能或性能上的限制。本文介绍了TFS，一种利用TEE提供的安全能力来引导新安全协议的云文件系统，这些协议能满足现实世界中在安全、功能和性能方面的要求。通过全面的安全性和性能分析，我们证明TFS能确保更强的安全保障，同时相对于现有系统仍能提供实用性和性能；与广泛使用的NFS相比，TFS在微基准测试中实现了高达2.1倍的加速，而在大多数宏基准测试工作负载中开销低于1倍。TFS表明，组织无需为了获得外包的功能和性能优势而牺牲文件系统的安全性。