A Decidable Notion of Timed Non-Interference

We present a notion of non-interference which embodies the notion of time. It is useful to verify the strength of a system against attacks depending on the frequency of certain actions. In particular we give a decidable definition of non-interference which can be checked by using existing verification tools. We show an application example of our notion of non-interference by defining a variant of the classical Fischer's mutual exclusion protocol and by analyzing its strength against attacks.