Jose Luis Vivas and Nobuko Yoshida
 
Recently programming languages have been designed to support mobile
code, i.e. higher-order code that is transferred from a remote
location or domain and executed within the local environment. This may
expose the internal interfaces and objects within a location to
attacks by mobile code. In this work, we propose an extension of
notations based on the Higher-Order Pi-calculus with a primitive
operator whose role is to protect internal interfaces by dynamically
restricting the visibility of channels. The usefulness of these
operators is illustrated by applications involving resource access
control. We show how restrictions on the behaviour of processes based
on the notion of process type, and intended to be checked statically,
can be enforced dynamically with the aid of the filter operator.