Poster: towards formal verification of DIFC policies

Decentralized information flow control (DIFC) is a recent important innovation with flexible mechanisms to improve the availability of traditional information flow models. However, the flexibility of DIFC models also makes specifying and managing DIFC policies a challenging problem. The formal policy verification techniques can improve the current state of the art of policy specification and management. We show that in general these problems of policy verification of the main DIFC systems are NP-hard, and show that several subcases remain NP-complete. We also propose an approach of model checking to solve these problems. Experiments are presented to show that this approach is effective.