Enforcing current-state opacity through shuffle in event observations

Checking and Enforcing Security through Opacity in Healthcare Applications

The Internet of Things (IoT) is a paradigm that can tremendously revolutionize health care thus benefiting both hospitals, doctors and patients. In this context, protecting the IoT in health care against interference, including service attacks and malwares, is challenging. Opacity is a confidentiality property capturing a system’s ability to keep a subset of its behavior hidden from passive obs...

Enforcing opacity of regular predicates on modal transition systems

Given a labelled transition system LTS partially observed by an attacker, and a regular predicate Sec over the runs of LTS, enforcing opacity of the secret Sec in LTS means computing a supervisory controller K such that an attacker who observes a run of K/LTS cannot ascertain that the trace of this run belongs to Sec based on the knowledge of LTS and K. We lift the problem from a single labelle...

Verification of initial-state opacity in security applications of discrete event systems

In this paper, we formulate and analyze methodologies for verifying the notion of initialstate opacity in discrete event systems that are modeled as non-deterministic finite automata with partial observation on their transitions. A system is initial-state opaque if the membership of its true initial state to a set of secret states remains opaque (i.e., uncertain) to an intruder who observes sys...

Enforcing K-Safeness in Controlled State Machines

Vowel Harmony, Opacity, and Finite-State OT

In this paper I propose cyclic and stratal extensions to FiniteState Optimality Theory as treatments for vowel harmony and for opaque phenomena more generally. I develop a model of grammar and an accompanying set of constraints within a software model built on the opensource PyPhon toolkit—a computational implementation of OT’s Gen and EVAL algorithms. 0 Constraint-based grammars and typology S...