Application of SDR (Software Defined Radio) technology for recovery of signals of side electromagnetic radiation of video tract

This article presents the results of recovering signals of spurious electromagnetic radiation of a video path using an SDR receiver. This work demonstrates the existence of a potential risk of leakage of confidential information through a technical channel of information leakage due to spurious electromagnetic radiation of a video path, bypassing traditional cryptographic and physical methods of information protection. An attack can be carried out by an attacker without special technical knowledge and special professional expensive equipment. The presented stand makes it possible to simplify research related to spurious electromagnetic radiation, as well as to apply this technology to build a learning process in this domain. In the course of the work, a description of the concept of a technical channel of information leakage and a brief description of the side electromagnetic radiation of the video path are given. The following briefly describes the SDR technology, the selected USRP B210 receiver, and the cross-platform open source GNU Radio software package. The demonstration stand is described in detail and the results of image reconstruction are given. In addition, two stages of the development of a demonstration stand are considered: using a simulation signal and a real intercepted signal. A demonstration stand with simulation signals serves to develop a user's understanding of the properties of spurious electromagnetic radiation, as well as possible obstacles to converting an intercepted signal into an image. The studies of the real intercepted signal were carried out on a monitor with a set resolution of 1280×1024 and a screen refresh rate of 60 Hz. An analog VGA (Video Graphics Array) interface was used to connect the monitor. The dependence of the quality of the reconstructed image on the set sampling frequency of the SDR receiver is shown.