Mitigating the effect of free riders in distributed systems: a trust-based approach

Distributed systems such as the grid, the cloud, and wireless sensor networks (WSNs) often involve cooperation and consequently require secure resource sharing across organisational boundaries. This adds an extra overhead that might negate the benefits of using these systems. WSNs and P2P services have similar underlying technologies and similar applications. One major problem hindering the success of these ubiquitous services is free riding. Many free riding algorithms proposed in the literature assume that all sensors are honest and collusion-free. These assumptions do not hold in environments such as WSNs and P2P, where autonomy and public subscription are key attributes. In this paper, we propose a free riding mitigation algorithm to countermeasure two types of attacks, namely dishonesty and collusion. We also conduct extensive experiments to evaluate our proposed solution.