Title
Incremental Observer Reduction Applied to Opacity Verification and Synthesis.
Abstract
With the proliferation of communication networks and mobile devices, the privacy and security concerns on their information flow are raised. Given a critical system that may leak confidential information, the problem consists of verifying and also enforcing opacity by designing supervisors, to conceal confidential information from unauthorized persons. To find out what the intruder sees, it is required to construct an observer of the system. In this paper, we consider incremental observer generation of modular systems, for verification and enforcement of current state opacity. The synchronization of the subsystems generate a large state space. Moreover, the observer generation with exponential complexity adds even larger state space. To tackle the complexity problem, we prove that observer generation can be done locally before synchronizing the subsystems. The incremental local observer generation along with an abstraction method lead to a significant state space reduction compared to traditional monolithic methods. The existence of shared unobservable events is also considered in the incremental approach. Moreover, we present an illustrative example, where the results of verification and enforcement of current state opacity are shown on a modular multiple floor/elevator building with an intruder. Furthermore, we extend the current state opacity, current state anonymity, and language based opacity formulations for verification of modular systems.
Year
Venue
DocType
2018
arXiv: Logic in Computer Science
Journal
Volume
Citations 
PageRank 
abs/1812.08083
1
0.35
References 
Authors
0
3
Name
Order
Citations
PageRank
Mona Noori Hosseini1284.85
Bengt Lennartson2934118.87
Christoforos N. Hadjicostis31425127.48