Privacy analysis and enhancements for data sharing in *nix systems

In this paper, we analyse the data sharing mechanisms of *nix systems and identify an immediate need for better privacy support. For example, using a simple insider attack we were able to access over 84 GB of private data at one organisation of 825 users, including 300 000 e-mails and 579 passwords to financial and other private services websites, without exploiting any technical vulnerability. We present two solutions to address this problem: 1. an administrative auditing tool which can alert administrators and users when their private data is at risk; 2. a new View Based Access Control (VBAC) mechanism which provides stronger and yet convenient privacy support. We also describe a proof-of-concept filesystem-based implementation and performance analysis of VBAC. Our evaluations with three well-known filesystem benchmarks show little overhead of using VBAC. Copyright © 2008, Inderscience Publishers.