RU2541931C1 - Apparatus for protecting computers and components thereof from unauthorised activity - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: apparatus for protecting computers comprises: a printed-circuit board 14 with circuit components, power supply contacts of the apparatus for protecting computers 1 and 2, power supply contacts GShS 3 and 4, an output contact 1 GShS 5, an output contact 2 GShS 6, GShS7, a low frequency amplifier 8, a mid-frequency amplifier 9, a high frequency amplifier 10, a high-pass filter 11, an amplitude detector 12, an audio signalling device 13, an electrodynamic audio signal emitter 15, variable resistors R2, R3, R4, R5, separating capacitors C1, C2, C3, installed jumper contacts P1, P2, P3.

EFFECT: higher reliability of protecting information from unauthorised access and loss of information due to secondary electromagnetic radiations and stray pickup.

3 cl, 2 dwg, 1 tbl

Description

The invention relates to the field of radio engineering and electronics and can be used to protect computers and their components from unauthorized activities and to prevent information leakage as a result of spurious electromagnetic radiation and interference (PEMIN).

An effective way to prevent information leakage from computers and their components from unauthorized activities is to actively mask radio-frequency electromagnetic radiation using computer protection devices (USC) with noise signal generators.

The most important requirements for computer protection devices with noise signal generators are:

the broadband spectrum of the output signal, dictated by the broadband side electromagnetic radiation;

uniformity of the spectral power density of the noise signal;

stability of noise generation mode;

availability of performance monitoring;

high efficiency;

small dimensions and weight;

ease of use.

A device based on a noise generator is known from the prior art, comprising first and second interconnected oscillators installed in a screen body with first, second and third asymmetrical strip lines. Each of the oscillators is made on two transistors in a push-pull circuit with a common emitter, the first, second and third asymmetrical strip lines are made in the form of a three-way spiral of Archimedes, the base of the first transistors of the first and second oscillators and the base of the second transistors of the first and second oscillators are paired and connected to the initial section of the first asymmetric strip line connected to the first output of the first resistor, the second output of which is connected to the housing. The collectors of the transistors of the first and second oscillators are connected to the initial sections of the second and third asymmetric strip lines, the ends of the second and third asymmetric strip lines are connected and through the second resistor are connected to the positive input of the power source connected through the third resistor to the end of the first asymmetric strip line, the first capacitor connected between the second and third asymmetric strip lines, the second and third capacitors are connected between the first and third non-symmetrical metric strip lines, and the output of the generator can be any point of the second and third asymmetric strip lines (patent RU 2097906, H03B 29/00, published: 11.27.97, Bull. No. 33).

The disadvantages of this technical solution are the relatively narrow spectrum of the output signal, limited to both the low-frequency and high-frequency spectral regions, the relatively low uniformity of the spectral power density of the noise signal.

A radio masking device is known from the prior art, comprising a noise generator and an active antenna circuit, in which the noise generator is a system of two generators interconnected by a communication element, the first generator comprising a non-linear amplifier with inertial auto-bias, a delay line, an output and an input of a non-linear amplifiers are interconnected by a delay line, the second generator contains a nonlinear amplifier, an adjustable delay line, the input and output of a nonlinear amplifier are interconnected p adjust- able delay line, the first generator output coupled to an input of the second generator via a capacitive coupling element, and the active antenna circuit is designed as a radiating type antenna magnetic dipole, one end of which is connected to the output of the second generator, and the other - to the common bus. The radio masking device has a low-frequency noise source, the output of which is connected to the input of the first generator (patent RU 2170493, H04K 3/00, published: July 10, 2001).

The disadvantages of this technical solution are the relatively narrow spectrum of the output noise signal, limited both from the low-frequency and high-frequency spectral regions, the relatively low uniformity of the spectral power density of the noise signal.

An information protection device containing a noise signal generator (GHS), a signal frequency converter, the outputs of the GHS and an additional signal shaper are connected to the first and second inputs of the prototype, the information processing system clock frequency unit (SOI) is used as an additional signal shaper, as well as an amplifier, the input of which is connected to the output of the signal frequency converter, and through an isolation capacitor and a variable resistor to the output terminal (patent RU 2421917, H04K 1/04, H03B 2 9/00, published: 06/20/2011, Bull. No. 17).

The disadvantages of the known information protection device are the relatively narrow frequency spectrum, the unevenness of the frequency response and the high spectral power of the peak values of the output noise signal, which reduces the reliability of the protection of information of technical equipment with a low information exchange rate having low-frequency side electromagnetic radiation, such as a keyboard, printer, scanner and other means.

The problem to which the claimed technical solution is directed is to expand the spectrum of the output noise signal in both the low-frequency and high-frequency spectral regions, equalize the spectral power density of the noise signal, the ability to adjust the level of the noise signal in four frequency bands, and adjust the spectral density of the noise power signal and noise signal, which together increases the reliability of protection of information on spurious electromagnetic emissions and interference of all those the technical means involved in information processing, including devices with a low information processing speed.

The problem is solved due to the fact that in the known information protection device containing a printed circuit board with circuit elements, a noise signal generator, contacts for connecting a power source, isolation capacitors, a broadband amplifier, variable resistors, the presence of structural elements and communication between the elements allowed to obtain a wideband noise a signal in the frequency range 10 kHz - 2 GHz with a power level of 10 dBm ± 2. Distinctive features of the proposed technical solution: the presence of structural elements, in particular, a noise signal generator with two output signals, a low-frequency amplifier, a medium-frequency amplifier, a high-frequency amplifier, while the outputs of the low, medium, and high-frequency amplifiers are connected via adjustable variable resistors to the radiating elements UZK antennas, high-pass filter (HPF), amplitude detector, sound alarm device, contacts of installed jumpers P1, P2, P3, the presence of communication between These elements allowed us to complete the task.

In addition, the proposed computer protection device is characterized by the presence of a resistor and an LED, forming a system of visual indication and control of the supply voltage of the device.

The technical result is achieved due to the fact that in the development of the design and the necessary connections of the elements of the computer protection device, a horizontal circuit breaker with two output signals is used, low, medium and high frequency amplifiers in conjunction with installed jumpers, variable resistors and elements of radiating antennas allowed to obtain a technical result, consisting c: expanding the spectrum of the output noise signal to the low and high frequencies from 0.2 kHz to 2800 MHz, increasing the uniformity of the spectral density the power of the noise signal, the spatial emission of noise signals in a wide frequency range from 0.2 kHz to 2800 MHz, increasing the reliability of the protected information, the ability to adjust the levels of noise signals in four frequency bands, the ability to adjust the spectral power density of the noise signal from 10 to 78 dB, the presence of a sound alert about the malfunction of the device, the presence of visual indication and control of the supply voltage of the computer protection device.

The technical problem solved by the developed technical solution consists in developing the design and the necessary connections of the elements of the computer protection device (UZK). UZK contains: printed circuit board 14 with circuit elements, UZK 1 and 2 power supply contacts, ГСС 3 and 4 power supply contacts, ГСС 5 output contact 1, ГСС 6 output 2 contact, ГСС 7, low-frequency amplifier 8, medium-frequency amplifier 9, amplifier high frequencies 10, while the outputs of the amplifiers of low, medium and high frequencies are connected through adjustable variable resistors to the elements of the emitting antennas UZK, high-pass filter (high-pass filter) 11, amplitude detector 12, sound alarm device 13, indicator LED VD1, constant resistor R1, variable resistors R2, R3, R4, R5, isolation capacitors C1, C2, C3, contacts of installed jumpers П1, П2, П3, 1 GHS output through an isolation capacitor C1 is connected to the input of the low-frequency amplifier 8 and to the variable resistor R3, the middle terminal of which is connected to element U2 of the ultrasonic ultrasonic transducer antenna, the output of the low-frequency amplifier through a variable resistor R2 is connected to element A1 of the radiating antenna UZK, the output 2 of the main circuit is connected to the input of the high-pass filter 11, to the isolation capacitor C3 and through the isolation capacitor C2 to the input of the force medium frequency amplifier 9, the output of the medium-frequency amplifier 9 through a variable resistor R4 is connected to the E3 element of the ultrasonic ultrasonic scanner, the output of the high-pass filter 11 is connected to the input of the high-frequency amplifier 10, the output of which through the variable resistor R5 is connected to the element E4 of the ultrasonic ultrasonic antenna the detector 12 through the isolation capacitor C3 is connected to the output 2 GShS, the output of the detector is connected to a sound alarm device 13.

The computer protection device may contain a resistor and an LED, forming a system of visual indication and control of the device’s supply voltage.

The computer protection device differs in that it can be implemented in two design versions, for installation in a free PCI bus slot and mounted on a DVI cable.

The presence of a causal relationship between the totality of the essential features of the claimed object and the achieved technical result is shown in table 1.

The technical result provided by the given set of features is to expand the spectrum of the output noise signal to low and high frequencies from 0.2 kHz to 2800 MHz, increase the uniformity of the spectral power density of the noise signal, the spatial emission of noise signals in a wide frequency range from 0.2 kHz up to 2800 MHz, increasing the reliability of protected information, the ability to adjust the levels of noise signals in four frequency bands, the ability to adjust the spectral density of noise power a signal from 10 to 78 dB, the presence of an audible warning of a device malfunction, the presence of visual indication and control of the device's supply voltage.

The invention is illustrated by drawings, which depict:

figure 1 is a connection diagram of a computer protection device;

figure 2 - spectrograms of informative PEMI and their noise by a noise signal.

The computer protection device comprises: a printed circuit board 14 with circuit elements, power contacts of the computer protection device 1 and 2, power supply contacts of the power supply 3 and 4, output contact 1 of the power supply 5, output contact 2 of the power supply 6, power supply 7, low-frequency amplifier 8 , a medium-frequency amplifier 9, a high-frequency amplifier 10, while the outputs of the low, medium and high-frequency amplifiers are connected via adjustable variable resistors to the elements of the UZK emitting antennas, a high-pass filter (HPF) 11, an amplitude detector 12, an audio signal device alizatsii 13, an electrodynamic transducer 15 beeps, variable resistors R2, R3, R4, R5, isolating capacitors C1, C2, C3, P1 contacts installed jumper, P2, P3.

The output 1 of the HSS through an isolation capacitor C1 is connected to the input of the low-frequency amplifier 8 and to the variable resistor R3, the middle output of which is connected to the element E2 of the ultrasonic ultrasonic scanning antenna. The output of the low-frequency amplifier through a variable resistor R2 is connected to the element E1 of the ultrasonic ultrasonic emitting antenna. The GSH output 2 is connected to the input of the high-pass filter 11, to the isolation capacitor C3 and, through the isolation capacitor C2, to the input of the medium-frequency amplifier 9. The output of the medium-frequency amplifier 9 is connected through an alternating resistor R4 to the element E3 of the ultrasonic ultrasonic scanning antenna. The output of the high-pass filter 11 is connected to the input of the high-frequency amplifier 10, the output of which is connected through an alternating resistor R5 to the element E4 of the ultrasonic ultrasound antenna. The amplitude detector 12 is connected through a separation capacitor C3 to the GSH output 2, the output of the detector is connected to an audible alarm device 13, which is connected to a sound electrodynamic emitter 15. The amplifiers 8, 9, 10 are powered through installed jumpers П1, П2, П3, if necessary can be set or removed by selecting the desired spectral density of the noise signal. The levels of the output noise signals in the four frequency bands can be changed smoothly using variable resistors.

As an illustrative example, figure 2 presents the spectrograms of informative spurious electromagnetic radiation (PEMI) and their noise by a noise signal. Instrumental measurements were carried out by a spectrum analyzer of the PSA E 4440A series (from 3 Hz to 26.5 GHz) from Agilent Technologies using the AI5-0 measuring antenna.

The indicated technical solutions allowed expanding the spectrum of the noise signal to the low and high frequencies, increasing the reliability of the information being protected, and protecting the information of technical equipment having low-frequency spurious electromagnetic radiation, which include a keyboard, printer, scanner, and other means, by a noise signal. Four radiating antenna elements are used as radiating devices of a broadband noise signal, which makes it possible to equalize the power spectral density of the noise signal uniformly.

Amplifiers 8, 9, 10 are made on integrated circuits, which allow amplifying signals from 0 to 3000 MHz for a coordinated load of 50 ohms. The high-pass filter is made according to the well-known scheme on LC elements. The amplitude detector is made on semiconductor diodes. The design of the sound alarm device provides protection of the electrodynamic sound emitter to prevent information leakage as a result of electro-acoustic transformations in a known manner described in the Z-9 collection of recommendations (Blocking of acoustoelectric transducers in electronic hardware and systems of general use. V.P. Aminov, I .V. Korovin, V.I. Rybalchenko, Moscow: Helios ARV, 2010).

Thus, using a device to protect computers and their components from unauthorized activity and information leakage, as a result of electromagnetic radiation and interference, electromagnetic side emissions and interference of the entire system will be noisy.

Prototypes of computer protection devices were made in two design options: for installation in a free PCI bus slot and mounted on a DVI cable.

Both versions yielded a positive result - during measurements, an informative signal at a distance of 0.2 to 1 m from the computer system unit could not be detected.

Prototypes were performed on a printed circuit board made of double-sided foil fiberglass 1.5 mm thick using SMD elements. The printed circuit board is placed in a cylindrical plastic case with a diameter of 32 mm and a length of 70 mm. The printed circuit board of the second option is made for installation in a free PCI slot for the bus of the computer system unit.

Tests of prototypes of computer protection devices confirm that the proposed device provides overlapping in the frequency range from 0.2 kHz to 2800 MHz with an adjustable noise signal level from 10 to 78 dB. Thus, the technical result is achieved.

The industrial feasibility of inventions follows from the description of computer protection devices in statics and dynamics and is confirmed by the fact of manufacturing and successful testing of prototypes with the achievement of the specified technical result.

Claims (3)

1. A device for protecting computers (UZK) and their components from unauthorized activity, comprising: a printed circuit board with circuit elements, a noise generator (GSH), contacts for connecting a power source, isolation capacitors, a broadband amplifier, variable resistors, characterized in that has two output signals, the ultrasonic testing device additionally contains a low-frequency amplifier, a medium-frequency amplifier, a high-frequency amplifier, while the outputs of the low, medium and high-frequency amplifiers are connected via an adjustable Variable resistors to the elements of the ultrasonic ultrasonic transducer antennas, high-pass filter (HPF), amplitude detector, sound signaling device, electrodynamic sound emitter, contacts of installed jumpers П1, П2, П3, GSH output 1 through an isolation capacitor C1 connected to the input of the low-frequency amplifier 8 and a variable resistor R3, the middle terminal of which is connected to the E2 element of the ultrasonic ultrasonic scanning antenna, the output of the low-frequency amplifier through the variable resistor R2 is connected to the element E1 of the ultrasonic ultrasonic scanning antenna, output 2 is connected to the input of the high-pass filter 11, to the isolation capacitor C3 and through the isolation capacitor C2 to the input of the medium-frequency amplifier 9, the output of the medium-frequency amplifier 9 is connected through an alternating resistor R4 to the element E3 of the ultrasonic transducer antenna, the output of the high-pass filter 11 is connected to the input of the amplifier high-frequency frequencies 10, the output of which through the variable resistor R5 is connected to the ultrasonic scanning element of the ultrasonic detection antenna element E4, the amplitude detector 12 is connected through the isolation capacitor C3 to the output 2 of the emergency supply signal, the output of the detector is connected to the device an audible alarm 13, an electrodynamic emitter of sound signals 15, while the ultrasonic scanner works with an expanded spectrum of the output noise signal in the low and high frequencies from 0.2 kHz to 2800 MHz, providing spatial emission of noise signals in a wide frequency range from 0.2 kHz up to 2800 MHz, increasing the uniformity of the spectral power density of the noise signal, increasing the reliability of information protection, the ability to adjust noise signal levels in four frequency bands, thereby protecting information and channels stray electromagnetic radiation and interference (PEMIN) with regulation of the spectral noise signal the power density of 10 to 78 dB. 2. The computer protection device according to claim 1 is characterized in that it can contain a resistor and an LED, forming a system of visual indication and control of the device’s supply voltage. 3. The computer protection device according to claim 1 is characterized in that it can be implemented in two structural versions, for installation in a free PCI bus slot and mounted on a DVI cable.

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