A secure file sharing service for distributed computing environments

Distributed cryptographic file systems enable file sharing among their users and need the adoption of a key management scheme for the distribution of the cryptographic keys to authorized users according to their specific degree of trust. In this paper we describe the architecture of a basic secure file sharing facility relying on a multi-party threshold-based key-sharing scheme that can be overlaid on top of the existing stackable networked file systems, and discuss its application to the implementation of distributed cryptographic file systems. It provides flexible access control policies supporting multiple combination of roles and trust profiles. A proof of concept prototype implementation within the Linux operating system framework demonstrated its effectiveness in terms of performance and security robustness.