Model checking usage policies

We propose a model for specifying, analysing and enforcing
safe usage of resources.
Our usage policies allow for parametricity over resources,
and they can be enforced through finite state automata.
The patterns of resource access and creation are described through
a basic calculus of usages.
In spite of the augmented flexibility given by resource creation
and by policy parametrization, we devise an efficient (polynomial-time)
model-checking technique for deciding when a usage is resource-safe,
i.e. when it complies with all the relevant usage policies.