Method and device for identifying risks of cyberattacks

Method of identification of risks of cyberattacks on a programmable logic controller, the method being implemented by a data processing device comprising a processing unit and a memory, the method comprising:

• the generation, by the device, of a digital representation of a minimized finite-state transducer based on a specification of a controller logic of the programmable logic controller, the minimized finite-state transducer comprising a set of source states, a set of destination states, and a set of transitions, each transition starting from a source state to a destination state based on a input data value;
• the generation and the storage into the memory of a second computer file, based on a first computer file identifying a subset of sensitive states among the set of states, the second file comprising a list of critical transitions associated with the sensitive states, and for each transition, a list of the input data;
• and
• the generation and the storage into the memory of a fourth computer file, based on a third computer file indicating the presence or not of a risk of corruption on at least each input data element contained in the second file, the fourth file indicating, among the input data, input data to be protected which are both associated with critical transitions and with a risk of corruption, these input data being at risk for a cyberattack.