Method and system for detecting a cyber-attack on a machine controller
For detecting a cyber-attack on a machine controller, a concurrent simulation of the machine is run in a secured access domain. From the machine controller actual control data are transmitted to the machine and resulting monitoring data are transmitted to a monitoring device. Furthermore, sensor data of the machine are transmitted to the concurrent simulation on a first secured transmission path. Based on the sensor data, the concurrent simulation simulates an operational behavior of the machine, thus inferring simulated monitoring data. The simulated monitoring data are then compared with the resulting monitoring, and an alarm signal is triggered depending on the comparison.
1. A computer-implemented method for detecting a cyber-attack on a machine controller controlling a machine, the method comprising:
a) running a concurrent simulation of the machine on a computer in a secured access domain;
b) transmitting, from the machine controller, actual control data to the machine and resulting monitoring data to a monitoring device;
c) transmitting sensor data of the machine to the concurrent simulation on a first secured transmission path;
d) simulating, by the concurrent simulation, an operational behavior of the machine based on the sensor data, thus inferring simulated monitoring data;
e) comparing the simulated monitoring data with the resulting monitoring data; and
f) triggering an alarm signal depending on the comparing.
2. The method according to claim 1 , wherein the concurrent simulation is implemented as a digital twin continuously supplied with sensor data of the machine and continuously simulating its operational behavior.
3. The method according to claim 1 , wherein the resulting monitoring data comprise sensor data, actual control data and/or operational data of the machine.
4. The method according to claim 1 , wherein the resulting monitoring data are transmitted on a second secured transmission path from the machine controller and/or from the monitoring device to a comparator, which also receives the simulated monitoring data for the comparison with the resulting monitoring data.
5. The method according to claim 1 , wherein:
the resulting monitoring data comprise the actual control data;
the concurrent simulation evaluates an inverse simulation model of the machine, thus determining simulated control data which are compatible with the sensor data;
the simulated control data are compared with the actual control data; and
the alarm signal is triggered depending on the comparing.
6. The method according to claim 1 , wherein:
the sensor data comprise first measured data from a first sensor internal to the machine and second measured data from a second sensor coupled to the machine,
the second sensor is secured against external influence,
a physical compatibility of the first measured data with the second measured data is tested by the concurrent simulation, and
an alarm signal is triggered depending on the test.
7. The method according to claim 6 , wherein the first measured data and the second measured data are weighted by different weight factors in the concurrent simulation.
8. The method according to claim 1 , wherein:
the simulated monitoring data are transmitted on a third secured transmission path from the concurrent simulation to a condition monitoring system,
the condition monitoring system evaluates the simulated monitoring data to detect an anomalous behavior of the machine, and
an alarm signal is triggered depending on an evaluation.
9. The method according to claim 1 , wherein the secured access domain and/or a secured transmission path is secured:
by an isolation or separation from the internet;
by protecting against an access or data transfer from the machine controller;
by authenticating communication endpoints;
by protecting integrity or confidentiality of communicated data;
by detecting unauthorized alteration of communicated data;
by a unidirectional gateway; and/or
by a data diode.
10. A system for detecting a cyber-attack on a machine controller, the system comprising:
one or more hardware processors configured to perform a method according to claim 1 .
11. A computer program product, comprising a computer readable hardware storage device having computer readable program code stored therein, said program code executable by a processor of a computer system to implement a method for detecting a cyber-attack on a machine controller, according to claim 1 .
12. A non-transient computer readable storage medium storing a computer program product according to claim 11 .