Adaptive and Distributed Access Control in Cognitive Radio Networks

Cognitive Radio (CR) is a novel wireless technology communication that allows for adaptive configuration of the reception parameters of a terminal, based on the information collected from the environment. CR techniques may be applied to the resolution of emergency crisis to improve the spectrum utilization and the resilience of the wireless networks used by public safety organizations. Typically, such scenarios demand a mechanism for expressing and enforcing access control policies: that is, for stating what are the available resources (e.g. transmission/reception bandwidths), what are the parties that are allowed to access them and under what conditions. However, due to the intrinsically highly dynamic nature of such settings - in which unknown parties may suddenly appear and force a change in the configuration of other parties - it is extremely difficult to establish in advance what are the most suitable access control policies. Trust negotiation is a well-known approach for expressing and enforcing distributed access control policies which depend on two or more (initially mutually untrusting) parties. Such policies are determined on the fly by all the involved parties and do not require a centralized authority. In this work we present a trust negotiation-based framework which allows for the definition of highly expressive and flexible distributed access control policies and their efficient enforcement in cognitive radio networks.