Opacity of discrete event systems and its applications

In this paper, we investigate opacity of discrete event systems. We define two types of opacities: strong opacity and weak opacity. Given a general observation mapping, a language is strongly opaque if all strings in the language are confused with some strings in another language and it is weakly opaque if some strings in the language are confused with some strings in another language. We show that security and privacy of computer systems and communication protocols can be investigated in terms of opacity. In particular, two important properties in security and privacy, namely anonymity and secrecy, can be studied as special cases of opacity. We also show that by properly specifying the languages and the observation mapping, three important properties of discrete event systems, namely observability, diagnosability, and detectability, can all be reformulated as opacity. Thus, opacity has a wide range of applications. Also in this paper we provide algorithms for checking strong opacity and weak opacity for systems described by regular languages and having a generalized projection as the observation mapping.

[1]  Michael K. Reiter,et al.  Crowds: anonymity for Web transactions , 1998, TSEC.

[2]  Christoforos N. Hadjicostis,et al.  Notions of security and opacity in discrete event systems , 2007, 2007 46th IEEE Conference on Decision and Control.

[3]  Stéphane Lafortune,et al.  Failure diagnosis using discrete-event models , 1996, IEEE Trans. Control. Syst. Technol..

[4]  P. Ramadge,et al.  Supervisory control of a class of discrete event processes , 1987 .

[5]  Vitaly Shmatikov,et al.  Probabilistic Model Checking of an Anonymity System , 2004 .

[6]  C. Desclaux,et al.  Supervisory control of discrete-event processes with partial observations , 1988 .

[7]  Demosthenis Teneketzis,et al.  Active diagnosis of discrete-event systems , 1998 .

[8]  Vitaly Shmatikov.  Probabilistic analysis of an anonymity system , 2004, J. Comput. Secur..

[9]  R. Dingledine,et al.  Reputation in P2P Anonymity Systems , 2003 .

[10]  Christoforos N. Hadjicostis,et al.  Opacity-enforcing supervisory strategies for secure discrete event systems , 2008, 2008 47th IEEE Conference on Decision and Control.

[11]  Raja Sengupta,et al.  Diagnosability of discrete-event systems , 1995, IEEE Trans. Autom. Control..

[12]  Pavol Cerný,et al.  Preserving Secrecy Under Refinement , 2006, ICALP.

[13]  Feng Lin,et al.  On-line control of partially observed discrete event systems , 1994, Discret. Event Dyn. Syst..

[14]  Feng Lin,et al.  Why Event Observation: Observability Revisited , 1997, Discret. Event Dyn. Syst..

[15]  R. D. Brandt,et al.  Formulas for calculating supremal controllable and normal sublanguages , 1990 .

[16]  Maciej Koutny,et al.  Opacity generalised to transition systems , 2005, International Journal of Information Security.

[17]  Shahin Hashtrudi-Zad,et al.  Fault diagnosis in discrete-event systems: framework and model reduction , 2003, IEEE Trans. Autom. Control..

[18]  W. Wonham,et al.  Supervisory control of timed discrete-event systems under partial observation , 1995, IEEE Trans. Autom. Control..

[19]  Feng Lin,et al.  State estimation and detectability of probabilistic discrete event systems , 2008, Autom..

[20]  Maciej Koutny,et al.  Modelling Opacity Using Petri Nets , 2005, WISP@ICATPN.

[21]  Walter Murray Wonham,et al.  On observability of discrete-event systems , 1988, Inf. Sci..

[22]  Stéphane Lafortune,et al.  Safe diagnosability for fault-tolerant supervision of discrete-event systems , 2005, Autom..

[23]  A. Willsky,et al.  Observability of discrete event dynamic systems , 1990 .

[24]  P. Darondeau,et al.  Opacity enforcing control synthesis , 2008, 2008 9th International Workshop on Discrete Event Systems.

[25]  P. Ramadge.  Observability of discrete event systems , 1986, 1986 25th IEEE Conference on Decision and Control.

[26]  Benoît Caillaud,et al.  Concurrent Secrets , 2007, 2006 8th International Workshop on Discrete Event Systems.

[27]  Peter E. Caines,et al.  Classical and Logic-Based Dynamic Observers for Finite Automata , 1991 .

[28]  Nejib Ben Hadj-Alouane,et al.  Centralized and distributed algorithms for on-line synthesis of maximal control policies under partial observation , 1996, Discret. Event Dyn. Syst..

[29]  Feng Lin,et al.  Diagnosability of discrete event systems and its applications , 1994, Discret. Event Dyn. Syst..