  We consider a notion of non-interference for timed automata (TAs) that allows
to quantify the frequency of an attack; that is, we infer values of the minimal
time between two consecutive actions of the attacker, so that (s)he disturbs
the set of reachable locations. We also synthesize valuations for the timing
constants of the TA (seen as parameters) guaranteeing non-interference. We show
that this can reduce to reachability synthesis in parametric timed automata. We
apply our method to a model of the Fischer mutual exclusion protocol and obtain
preliminary results.
