Gate automata-driven run-time enforcement

Security and trust represent two different perspectives on the problem of guaranteeing the correct interaction among software components. Gate automata have been proposed as a formalism for the specification of both security and trust policies in the scope of the Security-by-Contract-withTrust (S×C×T) framework. Indeed, they watch the execution of a target program, possibly modifying its behaviour, and produce a feedback for the trust management system. The level of trust changes the environment settings by dynamically activating/deactivating some of the defined gate automata. The goal of this paper is to present gate automata and to show a gate automatadriven strategy for the run-time enforcement in the S×C×T.