Hardening Access Control and Data Protection in GFS-like File Systems

The Google File System (GFS) is a highly distributed, faulttolerant file system designed for large files and high throughput batch processing. We consider the first complete security analysis of GFS systems. We formalize desirable security properties with respect to the successful enforcement of access control mechanisms and data confidentiality by considering a threat model that is much stronger then in previous works. We propose extensions to the GFS protocols that satisfy these properties, and provide a comprehensive analysis of the extensions, both analytically and experimentally. In a proof-of-concept implementation, we demonstrate the practicality of the extensions by showing that they incur only a 12% slowdown while offering higher-assurance guarantees.