The Algorithm for constructing a digital fingerprint of a sensor based on a dynamic model of its output signal for data protection in automated systems

The article considers the problem of an intruder’s interference in the technological (e.g. automated) system operation by replacing an endpoint device (sensor) or its signal; it also considers approaches to detecting such interference. A brief overview of existing methods for detecting device substitution is provided. As a solution to the problem, it is proposed to identify the device by comparing some of its current parameters with reference parameters collected in advance. For the purposes of identifying an endpoint device, the author proposes to compare digital fingerprints (current and reference ones) constructed using dynamic models of the signal of this device. The main requirements for the input data are formulated. Ways for preliminary improving the input data are proposed in case the data do not meet the above requirements. The algorithm for creating a digital fingerprint is described with a detailed explanation of the mathematical apparatus used; the algorithm is also presented in a flowchart form. The application of the algorithm for the identifying purposes both in laboratory conditions (using a specially created test bench) and on real data from the functioning microclimate analysis system of the Center of Digital Solutions for Smart Grid of the Institute of Control Sciences of the Russian Academy of Sciences is considered.