A framework for current-state opacity under dynamic information release mechanism

Opacity is an important information-flow security property that characterizes the plausible deniability of a dynamic system for its “secret” against eavesdropping attacks. As property, underlying observation model key in modeling and analysis opacity. In this paper, we investigate verification current-state opacity discrete-event systems under Orwellian-type observations, i.e., allowed to re-interpret event based on future suffix. First, propose new called information release mechanism (DIRM). DIRM, when previous “hold on” events state-dependent. Then definition notion history-equivalence rather than standard projection-equivalence. This more suitable observations are not prefix-closed. Finally, show by constructing structure DIRM-observer, can be effectively verified DIRM. Computational complexity as well illustrative examples proposed approach also provided. Compared with existing model, framework general sense information-release-mechanism state-dependent, partially released corresponding non-prefix-closed observations.