Industrial Automatic Control Systems and Controllers Annotation << Back On the Protection Against Register Transfer Level Circuit Trojans Titov A.S., Gordeev E.N. The paper considers topical in the information security of the automated systems area question of register transfer level circuits protection against Trojans. The mathematical apparatus of Boolean functions is used to model register transfer level circuits. Problems of analyzing Trojans presence in a modeled circuit, which disrupt the operation of it and cause a denial of service, have been studied. To solve these problems, methods, based on probabilistic algorithms, have been developed for checking the Boolean functions properties, namely: the property of preserving a constant and the property of the function depending on at most a fi xed number of its arguments The developed methods determine whether a circuit is vulnerable to denial of service. In this case, those input data of the circuit are clarifi ed in detail, when supplied, its availability is disrupted and a denial of service is accomplished. An asymptotic evaluation of the used in the system algorithms computational complexity was carried out. Their quantitative metrics are analyzed. The developed methodology is implemented programmatically. To conduct experiments, a subsystem has been created that simulates circuits with and without Trojans. Using it, optimal system confi guration parameters are selected for its effective functioning. The developed system is compared with other related to the presence of Trojans in register transfer level circuits analysis methods. Keywords: Boolean circuits, Boolean functions, probabilistic algorithms, availability breach, information security. DOI: 10.25791/asu.3.2024.1491 Pp. 03-18.