Simulating and modelling the impact of security constructs on latency for open loop control

Open loop control has commonly been used to conduct tasks for a range of Industrial Control Systems (ICS). ICS however, are susceptible to security exploits. A possible countermeasure to the active and passive attacks on ICS is to provide cryptography to thwart the attacker by providing confidentiality and integrity for transmitted data between nodes on the ICS network; however, a drawback of applying cryptographic algorithms to ICS is the additional communication latency that is generated. The proposed solution presented in this paper delivers a mathematical model suitable for predicting the latency and impact of software security constructs on ICS communications. The proposed model has been tested and validated against a software simulated open loop control scenario, the results obtained indicate on average a 1.3 percentage difference between the model and simulation.