Analytical model for calculating the effectiveness of the modified access control subsystem of the information security system against unauthorized access in automated systems

Abstract

The paper considers an analytical model for calculating the performance indicator of the access control subsystem of the information protection system against unauthorized access in an automated system, the use of which allows to significantly simplify the calculation and increase its accuracy. The dynamics of subsystem functioning is described using a stochastic Petri net using the Laplace transform. Using the example of the standard information protection system against unauthorized access “Strazh NT 4.0”, the results of calculations of probabilistic and temporal characteristics of the model “Starting the PC and identifying the user” are presented, which describes the functioning of the access control subsystem when it is modified by implementing additional authentication based on the regular user keyboard handwriting recognition. Obtaining analytical dependencies of transition probabilities between the states of a modified subsystem allows optimizing its operation and verifying compliance with the requirements for the probability of performing functional tasks in a given time, while increasing the overall level of security of the automated system.