• Article  

      Current-state opacity formulations in probabilistic finite automata 

      Saboori, A.; Hadjicostis, Christoforos N. (2014)
      A system is said to be current-state opaque if the entrance of the system state to a set of secret states remains opaque (uncertain) to an intruder - at least until the system leaves the set of secret states. This notion ...
    • Conference Object  

      Detectability in stochastic discrete event systems 

      Keroglou, C.; Hadjicostis, Christoforos N. (IFAC Secretariat, 2014)
      In this paper we define and analyze notions of detectability in stochastic discrete event systems (SDES). More specifically, we introduce the notions of A-detectability and AA-detectability which focus on characterizing ...
    • Article  

      Detectability in stochastic discrete event systems 

      Keroglou, C.; Hadjicostis, Christoforos N. (2015)
      A discrete event system possesses the property of detectability if it allows an observer to perfectly estimate the current state of the system after a finite number of observed symbols, i.e., detectability captures the ...
    • Conference Object  

      Initial state opacity in stochastic des 

      Keroglou, C.; Hadjicostis, Christoforos N. (2013)
      A non-deterministic finite automaton is initial-state opaque if the membership of its true initial state to a given set of secret states S remains opaque (i.e., uncertain) to an intruder who observes system activity through ...
    • Conference Object  

      Opacity formulations and verification in discrete event systems 

      Hadjicostis, Christoforos N.; Keroglou, C. (Institute of Electrical and Electronics Engineers Inc., 2014)
      In many emerging security applications, a property of a system, that may reveal important details about its behaviour, needs to be kept secret (opaque) to outside observers (intruders). Motivated by such applications, ...
    • Conference Object  

      Opacity verification in stochastic discrete event systems 

      Saboori, A.; Hadjicostis, Christoforos N. (2010)
      Motivated by security and privacy considerations in applications of discrete event systems, various notions of opacity have been introduced. Specifically, a system is said to be current-state opaque if the entrance of the ...
    • Article  

      Probabilistic system opacity in discrete event systems 

      Keroglou, C.; Hadjicostis, Christoforos N. (2018)
      In many emerging security applications, a system designer frequently needs to ensure that a certain property of a given system (that may reveal important details about the system’s operation) be kept secret (opaque) to ...
    • Conference Object  

      Probabilistic system opacity in discrete event systems 

      Keroglou, C.; Hadjicostis, Christoforos N. (Institute of Electrical and Electronics Engineers Inc., 2016)
      In many emerging security applications, a system designer frequently needs to ensure that a certain property of a given system (that may reveal important details about the system's operation) be kept secret (opaque) to ...
    • Article  

      Verification of detectability in Probabilistic Finite Automata 

      Keroglou, C.; Hadjicostis, Christoforos N. (2017)
      In this paper we analyze state estimation in stochastic discrete event systems (SDES) that can be modeled as probabilistic finite automata (PFAs). For a given PFA, we obtain the necessary and sufficient conditions that ...