This paper investigates a security problem of simultaneously addressing two types of attacks:Eavesdropping and infiltration.The authors model the target system as a discrete-event system(DES)with subsets of concealabl...This paper investigates a security problem of simultaneously addressing two types of attacks:Eavesdropping and infiltration.The authors model the target system as a discrete-event system(DES)with subsets of concealable events and protectable events,in order to make the proposed methodology applicable to various practical systems and employ two existing works of DES security:Degree of opacity and state protection.Specifically,the authors consider that all protectable events are observable,and some observable events are concealable.In addition,protectable events cannot be protected once they are concealed.Given such a constraint,the goal is to figure out which events to conceal and which transitions to protect so that the prescribed requirements of degree of opacity and state protection are satisfied.In this work the authors decide which events to conceal as all transitions of a given event label are concealed or not concealed.The proposed problem formulation also requires a solution to only involve absolutely necessary protectable events in order for the system to avoid superfluous protection costs.The authors first examine a general version of our security problem with an intuitive algorithm to compute acceptable solutions,and then present a special version which results in a reduced computation time compared to the general version.展开更多
基金funded by the Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery GrantJSPS KAKENHI under Grant Nos.21H04875 and 22KK0155.
文摘This paper investigates a security problem of simultaneously addressing two types of attacks:Eavesdropping and infiltration.The authors model the target system as a discrete-event system(DES)with subsets of concealable events and protectable events,in order to make the proposed methodology applicable to various practical systems and employ two existing works of DES security:Degree of opacity and state protection.Specifically,the authors consider that all protectable events are observable,and some observable events are concealable.In addition,protectable events cannot be protected once they are concealed.Given such a constraint,the goal is to figure out which events to conceal and which transitions to protect so that the prescribed requirements of degree of opacity and state protection are satisfied.In this work the authors decide which events to conceal as all transitions of a given event label are concealed or not concealed.The proposed problem formulation also requires a solution to only involve absolutely necessary protectable events in order for the system to avoid superfluous protection costs.The authors first examine a general version of our security problem with an intuitive algorithm to compute acceptable solutions,and then present a special version which results in a reduced computation time compared to the general version.
