RU2770790C1 - System of hidden protection of confidential acoustic information from unauthorized removal and a film coating for this system - Google Patents

Abstract

FIELD: confidential acoustic information protection.SUBSTANCE: inventions group relates to a system of hidden protection of confidential acoustic information from unauthorized removal and a film coating for it. The system of hidden protection of confidential acoustic information from unauthorized removal contains an absorbing-reflective film glued to the inner side of the glazing and piezoelectric emitters for excitation of mechanical vibrations of a chaotic nature on the elements of the window structure, which are fixed on a flexible conductive tape attached along the perimeter of the glazing on the specified film under the glazing seals in window construction. These piezo emitters are connected to the current-carrying elements of the said tape and connected to the vibroacoustic noise generator. The film is made flat and glued to the glazing with its edges placed under the seals of the window structure and is made multilayer, consisting of a spatter layer facing the glazing and cholesteric and low-emission layers located above it.EFFECT: increasing the degree of protection against unauthorized retrieval of information by means of laser location systems for remote listening by changing the polarization of the transmitted signal from linear to circular while simultaneously forming a chaotic masking noise on all elements of the window.4 cl, 5 dwg

Description

The invention relates to the field of optics, in particular to systems and devices for protecting speech information in enclosed spaces from listening and recording using laser location systems. In particular, we are talking about protecting speech information (as confidential acoustic information) from its remote reading using laser remote listening devices.

In modern conditions of the development of speech processing technologies, the protection of confidential acoustic information from possible leakage through technical channels ("Technical channels for the leakage of acoustic (speech) information. Classification and characteristics" Khorev A.A., J. "Special Equipment" No. 1, 1998 ) is one of the most important tasks in the overall set of measures to ensure the information security of the protected object. Among all types of leaks through technical channels, acoustic ones account for about 15%. Part of the data from this volume is extracted through vibroacoustic channels. Protection of information from leakage through these channels is relevant for commercial structures, organizations associated with the production of advanced science-intensive technologies, financial organizations, research institutions, institutions of the state and municipal government, etc. (“Information leak. Statistics in the world and in Russia”, https://poisk-zhuchkov.rf/blog/utechka-informaczii-statistika-v-mire-i-rossii/).

Optoelectronic (laser) channel for leakage of confidential acoustic speech information (“Acoustic reconnaissance equipment. Directional microphones and laser acoustic reconnaissance systems” Khorev A.A., https://cyberleninka.ru/article/n/sredstva-akusticheskoy-razvedki- napravlennye-mikrofony-i-lazernye-akusticheskie-sistemy-razvedki/viewer) is formed by probing with a laser beam the surfaces of objects vibrating under the action of the acoustic field of the speech signal and the enclosing structures of the premises (window panes, frames, mirrors, interior items, etc.) . The reflected laser radiation is modulated by a speech signal circulating in the room. It is received by a receiver of optical (laser) radiation and, due to special processing (demodulation), the original speech information is isolated.

Laser interception is difficult to detect with the naked eye because infrared wavelengths invisible to the human eye are used.

To prevent the interception of confidential acoustic information, special rooms without windows are used. These rooms are expensive to build and it is very uncomfortable to stay in them for a long time. When considering rooms with daylight access through window openings, it is necessary to protect the most vulnerable places from the point of view of protection from laser interception of confidential acoustic information - the windows of the room, through which the laser beam can penetrate the room from the outside.

Glass windows are light and elastic, they have large areas of impact of the sound signal from inside the room. Vibrations from an acoustic signal are also subject to frames and framing of windows - bindings, vents. To protect windows, special active protection systems are used, containing electric masking noise generators and vibration exciters and acoustic emitters attached to them. To protect windows, vibration exciters are installed on glass and frames, and acoustic emitters are placed near the glass surface from the side of the room or between the inner and outer frames. In the protection mode, the generators excite noise mechanical vibrations in the emitters, which are transmitted to the window elements. Mechanical noise masking interference prevents laser interception of protected confidential information from windows. If the frequency range and noise vibration level exceed, respectively, the frequency range and vibration level generated by speech, then conditions for blocking laser interception are created.

However, optical access through windows is also possible to many other elements of the room vibrating from an acoustic signal - posters, sheets, dishes, clocks, lampshades, etc. If you direct a probing laser beam through a window, focus the beam on these objects, you can get a speech-modulated reflected signal. To counter this method of intercepting confidential information, various curtains and opaque screens made of plastic or its combinations with other materials with various systems for blocking or distorting the signal passing through the glass have become widespread.

An analysis of well-known competitive solutions in this area revealed that there are currently several of them on the Russian market: Vibroacoustic protection system "Kamerton-5" (CJSC "Protection of electronic technologies"); Technical means of protecting speech information from leakage through the optical-electronic (laser) channel "Sonata-AV4L" (LLC "Anna"); Protective screen "Pelena-256" (LLC NPP "SPO", RU 202110).

Each of the development companies inevitably faces the following implementation problems:

1. The choice of components with high efficiency entails significant financial costs for development and production.

2. The installation of protective equipment involves changing the interior solutions implemented in the premises.

3. The impossibility of completely hiding the elements of information security systems and traces of protective measures.

4. Dependence on the source of energy supply.

5. Reducing the ergonomics of workplaces due to the possible deterioration of the acoustic environment during the operation of vibroacoustic noise devices.

Let's consider a commercially implemented, functioning, patented solution of the company NPP SPO LLC Protective screen "Pelena-256", protected by patent RU 202110.

This screen-type device for protecting confidential acoustic speech information from laser interception through the window, contains a canvas for covering the window opening, magnetic support type, fixed at one end on the window glass and made with a platform on the other end to support the canvas on it, while the canvas is placed in the window opening supported by a magnetic support type. The device is equipped with metal nickels, made with the possibility of magnetic connection with magnetic-type supports and carrying double-sided adhesive tape on one side.

According to the utility model, a screen-type device for protecting acoustic (speech) information from laser interception through a window contains a canvas for covering a window opening, which is made of polystyrene 3-5 mm thick, with an important spectral transmittance in the visible and infrared wavelength ranges, close to zero. A feature of the known solution is that it is used in addition to the pre-installed active information protection system, which, by placing vibration exciters on window panes, provides an oscillatory process in these glasses, which allows you to form a masking interference for laser radiation directed at the window and reflected from it.

From the point of view of achieving the required level of protection, this solution is quite effective, but somewhat cumbersome, multi-object, requires qualified control of the installation of racks and the presence of a pre-installed system of active information protection. This system significantly limits the effectiveness of the outdoor lighting of the room at the time of its use, implies an inevitable interference with the interior design of the room. In addition, this system is not hidden, it has a number of unmasking signs, it draws attention to the object of protection.

As a prototype, a solution was adopted for a system for protecting speech information from unauthorized removal, mounted on a window glass, and containing a power source and an acoustic signal generation unit. The system is equipped with an absorbing-reflecting film, a laser acoustic location system operation sensor mechanically fixed on the window glass, made in the form of a tape by a piezoelectric element mechanically connected to the absorbing-reflecting film, and a starting block. The output of the laser acoustic location system operation sensor is electrically connected in series through the starting unit to the input of the acoustic signal generation unit, while the first output of the acoustic signal formation unit is connected to the window glass, and the second output of the acoustic signal formation unit is connected to a piezoelectric element, the output of the power source is connected to the input block for generating acoustic signals and the input of the starting block, and the absorbing-reflecting film is mechanically fixed on the window glass (RU 2231928, H04K3/00, H03V29/00, publ. 06/27/2004).

The absorbing-reflecting film is made in the form of a positive hemisphere with a radius R related to the dimensions of the irradiated surface of the absorbing-reflecting film by the ratio R=(0.001-0.005) a, where a is the size of the irradiated surface of the absorbing-reflecting film. The laser radiation reflected from the window glass and the absorbing-reflecting film is modulated by an interfering sound frequency. In addition, due to at least double reflection of laser radiation from the surfaces of the window glass and the absorbing-reflecting film, as well as due to the absorption of radiation by the absorbing-reflecting film, the laser radiation entering the input of the receiver of the laser acoustic location system is significantly attenuated. Considering that the absorbing-reflecting film is made in the form of a positive hemisphere, the reflected laser radiation is scattered in a wide angle close to 180°.

The disadvantage of this solution in terms of implementing a system for protecting confidential speech information from unauthorized removal lies in the insufficient effectiveness of this protection due to the fact that the use of double attenuation of the signal (when it passes through glazing and an absorbing-reflecting film of a hemispherical shape) partially absorbs the signal, which is speech information, and its weakening. But even in a weak form, this signal still imitates speech information, even with distortions. The introduction of a hemispherical film creates uneven attenuation and distortion in the signal. Closer to the periphery, due to a change in the angle of incidence of the beam, these distortions will be greater than in the middle part of the film, which makes it possible to introduce a correlation into the recorded signal and modulate a distorted but readable signal shape. The introduction of one piezoelectric element as a source of additional sound radiation will allow the method of superimposing signals on each other to significantly distort the shape of the speech signal. This is a plus of the well-known solution, but this is not enough, since today there is a wide range of technical means that allow you to separate single mechanical vibrations (if you know the nature or source of their origin) from the main signal. In this case, the attenuated distorted signal, which is conditionally taken as an unauthorized voice signal, can be subjected to the same correlation and the output will be speech imitation. After all, someone who obtains confidential information does not need a voice as such, he needs the content of information in any form.

In addition, the means of protecting confidential acoustic information from unauthorized removal should have such a property as invisibility and secrecy and not have visually perceived signs indicating its type and, moreover, its design. In the known solution, the use of a hemispherical shape of the film unmasks the protection means and directly indicates the design features of the execution of this means. From the standpoint of the design, it is not entirely clear what a hemispherical film is in the known system. If this is a film, then it does not have a stable equilibrium shape in space; under its own weight, it always falls down, which does not allow it to be kept in the form of a hemisphere on the glazing. The shape of a hemisphere can be organized by creating an increased pressure in the area between this film on the outside of the glazing and the glazing itself. But in this case, the system acquires sufficient complexity in execution, since it is necessary to have a device for constant pumping of excess air into this zone, to ensure the sealing of this zone and control over the pressure and shape of the film.

The present invention is aimed at achieving a technical result, which consists in increasing the degree of protection against unauthorized retrieval of information by means of laser location systems for remote listening by changing the polarization of the transmitted signal from linear to circular while simultaneously forming a masking noise of a chaotic type on all elements of the window.

The specified technical result for the device is achieved by the fact that in the system of hidden protection of confidential acoustic information from unauthorized removal, mounted on a window structure with glazing and containing an absorbing-reflecting film placed on the inside of the glazing, at least one piezoelectric element mechanically connected to the absorbing reflective film for transmitting mechanical vibrations to the film, the absorbing-reflecting film is made flat and glued to the glazing with its edges placed under the seals of the window structure and is made multilayer, consisting of a spatter layer facing the glazing, and cholesteric and low-emission layers located on top of it, made in in the form of piezo emitters, piezoelectric elements for excitation of mechanical vibrations of a chaotic nature on the elements of the window structure are fixed on a flexible conductive tape used for attaching along the perimeter of the glazing to the specified film under the glazing seals in the window structure, while the piezo emitters are connected to the conductive elements of the specified tape and connected to the vibroacoustic noise generator.

As an embodiment, the absorptive-reflective film additionally includes, on the side facing the glazing, an adhesive layer for attaching the spatter layer to the glazing, and on top of the low-emissivity layer, an anti-scratch layer used as a front surface.

The specified technical result for the film is achieved by the fact that the film coating for the system of hidden protection of confidential acoustic information from unauthorized removal is made in the form of a multilayer film, including a spatter layer, a cholesteric layer and a low-emissivity layer arranged in series. Moreover, this coating may additionally include an adhesive layer on the side of the spatter layer, and an anti-scratch layer on the side of the low-emission layer.

These features are essential and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The present invention is illustrated by a specific example of execution, which, however, is not the only one, but clearly demonstrates the possibility of achieving the desired technical result.

In FIG. 1 - an image of a window glazing with a film coating of a system for protecting speech information from laser interception through the window;

fig. 2 - a fragment of a window system with the placement of piezo emitters on a conductive tape along the perimeter of the window glass;

fig. 3 is a schematic representation of the helical supramolecular structure of the film coating;

fig. 4 - characteristic peak of selective light reflection of a cholesteric liquid crystal;

fig. 5 shows a combination of coating layers for window glazing.

According to the present invention, a system is considered that provides covert protection of acoustic information (speech information in the first place) from reading through the use of laser means for remote listening. The system uses a coating that has the properties of absorption and reflection of laser radiation energy in a certain wavelength range, is connected by a module with piezoelectric emitters that create chaotic vibration on the glazing surface, which does not allow removing audio information from windows.

In the general case, the system of hidden protection of confidential acoustic information from unauthorized removal contains an absorbing-reflecting film placed on the inner side of the glazing, at least one piezoelectric element mechanically connected to the absorbing-reflecting film for transmitting mechanical vibrations to the film. In this case, the absorbing-reflective film is made flat and glued to the glazing with its edges placed under the seals of the window structure and is made multilayer, consisting of a spatter layer facing the glazing, and cholesteric and low-emission layers located above it. Piezoelectric elements made in the form of piezoelectric emitters for excitation of chaotic mechanical vibrations on window structure elements are fixed on a flexible conductive tape used for attaching along the glazing perimeter to the specified film under the glazing seals in the window structure. In this case, the piezo emitters are connected to the conductive elements of the specified tape and connected to the vibroacoustic noise generator.

Below is an example of a specific implementation of the utility model.

The system of hidden protection of confidential acoustic information from unauthorized removal (Fig. 1 and 2) is mounted on a window structure with glazing. A window structure is understood as a window frame 1 (metal or polymer plastic or wood or a combination of the mentioned materials), in the opening of which glazing 2 is placed (single glass or a double-glazed window made of both glass and transparent polymer sheets). A seal 3 is laid along the perimeter of the glazing (in this case, from inside the room), which is then pressed and fixed with a glazing bead 4 during window assembly.

The system comprises an absorbing-reflecting film 5 placed on the inside of the glazing and piezoelectric elements 6 mechanically connected to the absorbing-reflecting film to transmit mechanical vibrations to the film in the form of acoustic signals.

Piezoelectric elements 6 made in the form of piezoelectric emitters for emitting acoustic signals of a chaotic nature to the elements of the window structure are fixed on a flexible conductive tape 7 used to attach along the perimeter of the glazing on the specified film 5 under the seals 3 of the glazing in the window structure. The piezo emitters are connected to the conductive elements of the tape and are connected to a masking noise signal generator or a noise generator (the generators are not shown in the images of the figures). The assembly is fixed with glazing beads 4. Since the tape and the piezo emitters placed on it are hidden under the seals, they are not visually perceived. Piezo emitters perform the function of generators of noise acoustic masking interference in the form of hidden devices placed along the perimeter of the glazing (between glass with a film and a sealant), which are connected through a conductive tape to a vibroacoustic noise generator. The number of piezo emitters is determined by the area of the glazing.

As piezo emitters, you can use small-sized piezoelectric sound emitters ZP, offered for sale by the company "Aurora Elma" (they have a dimension in thickness from 0.5 to 2 mm with plate sizes from 5 to 100 mm). As a vibroacoustic noise generator, any generator on the market can be used, for example, brands with the index SV-4B or SV-4B1, which are electroacoustic transducers with built-in generators of electrical noise voltage, designed to build systems for protecting information from leakage through acoustic and vibroacoustic channels . Experimental tests have shown that the level of noise emitted by piezo emitters installed on the window does not interfere with the comfortable use of the room.

As piezo emitters, you can use small-sized piezoelectric sound emitters ZP, offered for sale by the company "Aurora Elma" (they have a dimension in thickness from 0.5 to 2 mm with plate sizes from 5 to 100 mm).

A feature of this design is that the use of several piezoelectric emitters makes it possible to obtain various modes of switching on these piezoelectric elements through the conductive elements of the tape. At the same time, it is taken into account that piezoelectric emitters belong to the category of simplified and simple in design electrical devices with a fairly wide range of output signal deviations. Such piezo emitters can be turned on simultaneously or in separate groups, providing a changing picture of acoustic interference on the window structure.

The absorbing-reflecting film is made as a multi-layered flat film and is glued to the glazing so that its edges are placed under the seals of the window structure. As a minimum implementation algorithm, this film consists of a spatter layer facing the glazing, and cholesteric and low-emission layers located on top of it, the latter facing outward from the glazing. This film is an absorbing-reflective coating glued to the glazing that blocks the laser signal in the IR spectrum. The film is placed inside the room by applying it to a window pane or double-glazed window from inside the room, prevents the removal of protected confidential acoustic information, reflecting and absorbing the probing laser beam. In this case, due to the mechanical vibration excited in the film, the reflected beam is modulated by the noise signal of the masking noise. Additional protection of information is achieved by imparting mechanical vibration to the glass itself.

This design, unlike the prototype and analogues, is easy to install and can be mounted on already installed double-glazed windows. As aesthetically as possible fits into the interior design of the room, without violating its original appearance.

The decision can be considered applicable en masse. The film from the inside of the window has practically no unmasking signs, it gives the glass only a light tint. Piezo emitters connected to a conductive tape are hidden along the perimeter of the window. The protected premises do not attract the attention of intruders. Reflection and absorption of light by the film is provided in the entire potentially dangerous wavelength range from visible to far infrared radiation. Being indoors, the coating does not deteriorate from external influences, dust and dirt do not accumulate on it, it retains the vibration amplitude without reducing the degree of information protection. Once applied, the coating is quite durable, does not require removal and re-installation, which reduces the degree of depreciation and labor intensity of use. The device allows enough daylight into the room, even when negotiations are taking place. In general, the system is not difficult to manufacture, operate and makes the protected room very comfortable for the personnel.

The claimed system is suitable for equipping any installed windows, including windows with opening sashes, without violating the interior design of the room. Allows you to improve working conditions in the room (provides secrecy from the outside of the room and the possibility of natural lighting). And always connecting the system to a power source provides continuous protection when needed.

Technologically, the system is the combined work of several elements: a film coating applied on the inside of the window glass, piezoelectric emitters placed along the glazing perimeter (between the glass and the seal) on top of the film, mechanically fixed on a conductive tape connected to a vibroacoustic noise generator.

The film coating (FIG. 5), ie the absorbent-reflective film, consists of a combination of film layers. The order of the layers is as follows (in the direction from the side to be adjoined directly to the glazing): liner 8, adhesive layer 9, closed by the liner and which must be removed before gluing the film to the glazing, spatter layer 10, cholesteric layer 11, low-emissivity layer 12 and being the outer (front) layer anti-scratch layer 13.

The key element of the film is the medium-located cholesteric layer 11 located between the low-emission 12 and spatter 10 layers. The cholesteric layer 11 has the property of 100% reflection of light in a certain spectral region by combining layers of right- and left-handed cholesteric (FIGS. 3 and 4).

The most complex type of ordering of liquid crystal molecules is cholesteric (cholesterics), formed by chiral (optically active) molecules containing an asymmetric carbon atom. This means that such molecules are mirror-asymmetric, in contrast to the mirror-symmetric molecules of nematics. An example illustrating the lack of mirror symmetry can be, for example, the left and right hands of a person, which we can never combine with each other. The cholesteric mesophase was first observed for derivatives of cholesterol, hence its name. Cholesterics are in many respects similar to nematics, in which a one-dimensional orientational order is realized; they are also formed by adding small amounts of chiral compounds (1-2 mol.%) to nematics. In this case, helical twisting of the molecules is additionally realized, and very often the cholesteric is called a twisted nematic. The periodic helical structure of cholesterics determines their unique feature - the ability to selectively reflect incident light, "working" in this case as a diffraction grating. At a fixed reflection angle, the interference conditions are satisfied only for beams of the same color, and the cholesteric layer (or film) appears to be colored in one color. This color is determined by the pitch of the helix P , which, at a normal angle of incidence of light, is simply related to the maximum wavelength of the reflected light. This effect of selective reflection of light with a certain wavelength by a cholesteric film is called selective reflection. Depending on the pitch of the helix, which is determined by the chemical nature of the cholesteric, it can be located in the visible, as well as in the IR and UV regions of the spectrum, defining wide areas for the use of the optical properties of cholesterics.

Cholesteric liquid crystals have a supramolecular helical structure with unique optical properties, one of which is selective light reflection. The selective light reflection wavelength (λ _max ) is related to the helix pitch P with the following relation:

where n is the average refractive index of the mesophase.

To ensure intense selective reflection, it is necessary to set the so-called. planar orientation of LC molecules, i.e. along the substrates (in this case, the spiral axis is along the normal to them). The reflected light is circularly polarized and, for example, for a left-handed helix, only left-handed circularly polarized light is reflected. Therefore, to obtain a film with 100% light reflection in a certain spectral region, it is necessary to make a two-layer film from a right- and left-handed cholesteric.

The width of the selective reflection peak is proportional to the anisotropy of the refractive index Δn :

For the visible and near-IR spectral regions, this value is usually 50-100 nm and is determined by the chemical structure of the cholesteric components (their polarizability), as well as the quality of the planar orientation of the liquid crystal.

The low emissivity layer 12 is inherently heat reflective. Solar radiation is made up of various components. It will include infrared and ultraviolet radiation invisible to the human eye, as well as the visible spectrum. The technology for the production of a heat-reflective layer uses these physical properties of light. This layer protects from the penetration of heat into the room by 90% and has a transparency of 70%, having a barely noticeable blue tint and not having a mirror effect.

An anti-scratch layer 13 is applied to the layer 12 of the low-emissivity film, which protects against mechanical damage.

The spatter layer 10 is capable of selectively retaining sunlight and thermal energy. Using magnetron sputtering, non-ferrous metal particles are added to the structural lattice of the polymer, which leads to an ideal ratio of light transmission and reflection of solar energy. The word sputter in translation from English means splashing or splashing, sputtering - spraying. A spatter layer is a coating that is made using advanced technology by spraying a metal of a certain thickness. In the process of manufacturing such a material, a positive charge is applied to the film base, and a negative charge is applied to the metal. Under the action of an electric discharge, metal elements rush to the base, covering it with a very thin and uniform layer. The spatter layer is designed to block thermal (infrared) radiation. In this case, heat should not so much be absorbed as reflected in this layer.

The combination of these layers is a unique coating for window glazing. The thickness of the layers used in the film combination is from 20 to 100 microns. Full adhesion of the layers is achieved by lamination, which makes it possible to obtain a high quality end product (Fig. 5).

In fact, the main layers involved in the transformation of the transmitted signal are the spatter layer 10, the cholesteric layer 11 and the low-emission layer 12, which form the protective coating. The anti-scratch layer is used to protect the main layers from the external environment and mechanical influences, and the adhesive layer with a liner is used to ensure convenient and quick attachment of the coating to the glazing. These last two layers are classified as auxiliary and allow the coating to be produced in the form of a finished and usable product.

When laser radiation passes through this protective coating, its polarization changes. Moreover, depending on the angle of incidence, the polarization changes from linear to circular, and the radiation depolarization is insignificant. The high transmission losses introduced by the film and the change in the polarization of the laser radiation will require an increase in the probing radiation power up to 400 times and, consequently, an increase in the laser radiation power up to 2000 mW, respectively.

From a practical point of view, the installation of a protective coating on window glazing narrows the range of possible laser means for intercepting confidential acoustic information, increases the probability of detecting probing radiation using visual infrared observation tools, or makes it necessary to bring the interception equipment closer to the window glazing at a distance of about 20-30 m, which also unmasks the fact of interception.

However, the use of only a protective film coating cannot completely exclude the possibility of intercepting confidential speech information from window panes by laser means. It is proposed to supplement the created solution with a vibroacoustic protection system, which is a conductive tape in the form of a flexible white board 10 mm wide with an adhesive layer, placed along the perimeter of the window between the glass on one side and pressed by a window seal on the other, on which piezoelectric emitters. The use of this property is realized by connecting the contacts of the conductive tape with a masking noise signal generator (noise generator). The generator activates all, either in groups or in a certain sequence of switching on (for this, a programmable switch on the processor can be used) piezoelectric emitters on the tape, they, in turn, excite all the elements of the window on which they are installed with a masking noise, i.e. glass, frame and film coating. After that, the protection of confidential speech information from laser interception through the window begins to function in full.

The invention is commercially interesting in that it involves both the integrated use of the solution (a protective coating in conjunction with a vibroacoustic protection system using the proposed masking noise generator connected to a conductive tape with ceramic piezo emitters fixed on it), and the possibility of separate use, namely, the installation of a coating on window glazing with a previously installed vibroacoustic protection system.

The declared solution to create a coating on window glazing for covert protection of confidential acoustic information from leakage using laser remote listening tools is directly related to the priorities and key tasks in view of the fact that the solution is aimed at creating new materials and developing the use of technologies based on it for further successful commercialization and satisfaction of the market demand for new research developments in the field of means of protecting confidential acoustic information.

Claims (4)

1. The system of hidden protection of confidential acoustic information from unauthorized removal, mounted on a window structure with glazing and containing an absorbing-reflecting film placed on the inside of the glazing, at least one piezoelectric element mechanically connected to the absorbing-reflecting film for transmitting mechanical vibrations to the film , characterized in that the absorbing-reflective film is made flat and glued to the glazing with the placement of its edges under the seals of the window structure and is made multilayer, consisting of a spatter layer facing the glazing and cholesteric and low-emission layers located on top of it, piezoelectric elements made in the form of piezoelectric emitters for excitation of mechanical vibrations of a chaotic nature on the elements of the window structure are fixed on a flexible conductive tape used to attach along the perimeter of the glazing to the specified film under the glazing seals i in a window structure, while the piezo emitters are connected to the conductive elements of the specified tape and connected to a vibroacoustic noise generator. 2. The system according to claim 1, characterized in that the absorbing-reflective film additionally includes, on the side facing the glazing, an adhesive layer for attaching the spatter layer to the glazing and, on top of the low-emissivity layer, an anti-scratch layer used as a front surface. 3. Film coating for a system of hidden protection of confidential acoustic information from unauthorized removal, characterized in that it is made in the form of a multilayer film that includes a spatter layer, a cholesteric layer and a low-emissivity layer arranged in series. 4. The film coating according to claim 3, characterized in that it additionally includes an adhesive layer on the side of the spatter layer, and an anti-scratch layer on the side of the low-emission layer.

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