Analysis of vulnerabilities of automated control systems for construction machinery and methods for preventing unauthorized control

Abstract

An on-board automated control system of a construction machine integrates satellite and inertial measurement channels, the computing loop of the controllers and the hydraulic drive of the working equipment, together with a telematics unit, a remote-control radio link, a service connector and a firmware update channel. Each of these interfaces forms a separate route to a single target state in which an actuator unit accepts a forged command. The material is a synthetic architecture of such a system. A probabilistic analysis of unauthorized access routes with an exhaustive enumeration of the configurations of protective measures was applied, the unit of analysis being a modelled configuration of protective measures, while eleven inputs were set by the author's assumptions and verified by separately substituting the lower and upper bound of every input. Without protection the modelled target probability is 73.49%, with all five measures it falls to 0.0717%, a reduction by a factor of 1,025. The ranking of single measures follows the number of routes a measure covers and the weight of the most probable of them rather than the magnitude of its attenuation coefficient, and the ranking reverses at a service-connector access probability of 0.457. The calculations indicate that in the architecture considered the decisive choice is not the hardening of one external interface but the placement of measures on the transition shared by every route. The relations obtained are stated as testable consequences of the adopted specification and describe model behaviour.