Annotation: The lecture discusses methods and means of protecting acoustic (speech) information: sound insulation, noise, reconciliation of voice recorders. The basic requirements and recommendations are given on the protection of speech information.

The methods of protection of acoustic (speech) information are divided into passive and active. Passive methods are aimed at the weakening of the immediate acoustic signals circulating indoors, as well as the products of electroacoustic transformations in WTCS and the CEC and connecting circuits. Active methods provide for the creation of masking interference and suppression / destruction of technical means of acoustic intelligence.

Soundproofing

The main passive method of protecting acoustic (speech) information is sound insulation. Selecting an acoustic signal by an attacker is possible if the signal-to-noise ratio lies in a specific range. The main purpose of the use of passive information security tools - Reduction of the signal-to-noise ratio at possible points of intercepting information by reducing the informative signal. Thus, sound insulation localizes radiation sources in a closed space in order to reduce the signal-to-noise ratio to the limit that eliminates or significantly impede acoustic information. Consider a simplified soundproofing scheme from the point of view of physics.

With fall acoustic wave On the border of surfaces with various specific planes, most of the incident wave reflects. The reflective surface ability depends on the density of the material from which it is made and the speed of propagation of the sound in it. Reflection acoustic wave It can be imagined as the result of the collision of air molecules M with molecules of the reflecting surface M. At the same time, if M \u003e\u003e M, then the speed of the massive ball is close to zero after impact. In this case, almost all kinetic energy acoustic wave turns into the potential energy of the elastic deformation of fixed balls. When the shape is restored, the deformed balls (surfaces) inform the air molecules hitting them, close to the original, but reverse in the direction - so the reflected wave occurs.

Little part acoustic wave It penetrates the soundproofing material and distributed in it, losing its energy.

For solid, homogeneous, building structures, the attenuation of acoustic signals characterizing the quality of sound insulation is calculated as follows (for medium frequencies):

Mass of fence, kg;

Sound frequency, Hz.

At the design stage of selected premises, when choosing enclosing structures, you must follow the following:

• as overlapping use acoustically inhomogeneous structures;
• as a floor, use structures installed on vibration insulators, or structures on an elastic basis;
• it is better to use suspended ceilings with high sound absorption;
• as walls and partitions, it is preferable to use multilayer acoustic inhomogeneous structures with gaskets from materials such as rubber, cork, fiberboard, MVP, and the like.

In any room, the most vulnerable from the point of view of acoustic intelligence are doors and windows.

Window glasses are strongly vibrated under pressure acoustic waveTherefore, it is advisable to separate them from frames with rubber gaskets. For the same reason, it is better to apply a triple or at least double glazing on two frames fixed in separate boxes. At the same time, on the outer frame, establish pinned glass, and between the boxes - sound absorbing material.

Doors have significantly smaller compared to other protective designs of surface densities of cloths and difficult by sealing gaps and slots. Thus, the standard door is very poorly protected, so doors with increased sound insulation should be applied. For example, the use of sealing pads increases the soundproofing of doors by 5-10 dB. It is better to install double doors with a tambour and vibrating junction from each other. The characteristics of the sound-absorbing properties of various designs are shown in Tables 14.1, 14.2.

Table 14.1.

A type	Design
		125	250	500	1000	2000	4000
Shield door lined with plywood on both sides	without strip	21	23	24	24	24	23
		27	27	32	35	34	35
Typical door P-327	without strip	13	23	31	33	34	36
	with porous rubber gasket	29	30	31	33	34	41

Table 14.2.

A type	Soundproofing (dB) at Hz frequencies
	125	250	500	1000	2000	4000
Single glazing
thickness 3 mm	17	17	22	28	31	32
4 mm thickness	18	23	26	31	32	32
thickness 6 mm	22	22	26	30	27	25
Double glazing with air interval
57mm (thickness 3 mm)	15	20	32	41	49	46
90 mm (Thickness 3 mm)	21	29	38	44	50	48
57mm (thickness 4 mm)	21	31	38	46	49	35
90 mm (thickness 4 mm)	25	33	41	47	48	36

The use of sound-absorbing materials has some features associated with the need to create an optimal ratio of direct and reflected from the barrier of acoustic signals. Excessive sound absorption reduces the signal level. The value of the impact of sound with various fences is given in Table 14.3.

Table 14.3.

Type of fence	Soundproofing (dB) at Hz frequencies
	125	250	500	1000	2000	4000
Brick wall	0,024	0,025	0,032	0,041	0,049	0,07
Wooden upholstery	0,1	0,11	0,11	0,08	0,082	0,11
Single glass	0,03	-	0,027	-	0,02	-
Plaster limestone	0,025	0,04	0,06	0,085	0,043	0,058
Felt (thickness 25mm)	0,18	0,36	0,71	0,8	0,82	0,85
Carpet with Vors.	0,09	0,08	0,21	0,27	0,27	0,37
Glass wool (thickness 9 mm)	0,32	0,4	0,51	0,6	0,65	0,6
Cotton fabric	0,03	0,04	0,11	0,17	0,24	0,35

Sound-absorbing materials - materials used for the interior decoration of the premises in order to improve their acoustic properties. Sound-absorbing materials may be simple and porous. In simple materials, the sound is absorbed as a result of viscous friction in the pores (foam concrete, gas station, etc.). In porous materials, in addition to friction in the pores there are relaxation losses associated with deformation of a non-rigid skeleton (mineral, basalt, cotton wool). Usually two types of material are used in combination with each other. One of the common types of porous materials is facing sound-absorbing materials. They are made in the form of flat plates ("AMGRAN", "ACINIT", "SILOKPOR", "Vibrastek-M") or relief structures (pyramids, wedges, etc.), disposed or closely, or at a short distance from solid construction Designs (walls, partitions, fences, etc.). Figure 14.4 shows an example of a sound-absorbing plate. For the production of plates such as "AMGRAN", use mineral or glass granulated Watts and binders consisting of starch, carboxylulose and bentonite. From the prepared mixture, 2 cm thick plates are formed, which after drying are subjected to trim (calibrated, grind and stain). The facial surface plate has a crack texture. The density of sound-absorbing material is 350-400kg / m3. Fastening sound-absorbing plates to the overlap, as a rule, is carried out using metal profiles.

Fig. 14.1.

Porous sound-absorbing materials are ineffective at low frequencies. A separate group of sound-absorbing materials is resonant absorbers. They are divided into membrane and resonator. The membrane absorbers are a stretched canvas (fabric), a thin plywood (cardboard) sheet under which there is a well damping material (material with high viscosity, for example, foam rubber, spongy rubber, construction felt, etc.). In this kind of absorbers, the absorption maximum is achieved on resonant frequencies. Perforated resonator absorbers are a system of air resonators (for example, Helmholtz resonators), at the mouth of which the damping material is located.

The level of the barrier is estimated at the following formula:

Consider an example of the sound insulation of fences and gender.

In the case when it comes to erecting a partition with high sound insulation properties, as an effective design, it is proposed to consider the partition on two independent frameworks with two layers of drying sheets on each side. In this case, a system consisting of two independent metal frames with a thickness of 50, 75 or 100 mm thick, which from two sides are trimmed with HBL sheets in two layers with a thickness of 12.5 mm each. When installing this design, all elements of metal frames, as well as the ends of the GVL sheets, are adjacent to all other structures, including carriers, through a layer of vibration insulating material with a thickness of 6 mm. Metal frames are mounted in parallel relative to each other with a gap of at least 10 mm to eliminate possible links among themselves. The inner space of the partition is filled with sound-absorbing basalt plates on a thickness equal to at least 75% of the total inner thickness of the partition. Air noise insulation index by partition on two frames of 100 mm with a total thickness of 260 mm is RW \u003d 58 dB, the partition based on 50 mm thick profiles provides a sound insulation value of RW \u003d 54 dB with a thickness of 160 mm

Existing wall.

Slabs made of glass staple fiber (2 layers of 20 mm).

Polyethylene film.

Screed 80mm.

Reinforcement net.

Gasket around the perimeter of the room from glass-staple plates (1 layer).

On the slab overlap, 2 layers of soundproofing material are stacked, for example, glass staple fiber. At the same time, the laying of a single layer of material with a thickness of 20 mm and a slightly large height of a suitable screed are starting to all walls of this room. The separating layer of a polyethylene film is set on top of the material, according to which a concrete leveling screed with a thickness of 80 mm is suitable, reinforced with a metal grid to give it increased mechanical strength.

To enhance sound insulation in rooms, acoustic screens can be installed on the propagation of sound in the most dangerous leakage directions. As a rule, screens are used to protect temporary premises.

For confidential conversations, so-called soundproofing cabins are also developed, which are divided into frame and frameless. The first have a metallic framework, which is mounted sound-absorbing panels. Cabins with two-layer sound-absorbing plates provide sound attenuation up to 35 ... 40 dB. Frameless type cabins are more efficient. They are collected from ready-made multilayer shields connected with soundproofing elastic gaskets. The effectiveness of such cabins lies in the range of 50 ... 55 dB.

Anyone who has something to keep secret from others, when using the phone sooner or later thinks about how to protect against listening to a telephone conversation. The problem of choosing the means of protection from the abundance of the existing on the Russian market. This task is of particular importance with the development of IP telephony technology.

When using the telephone, we will freely or unwittingly trust it with information that is sometimes confidential. These may be information relating to personal life, or personal data of employees of organizations. On the phone, information containing commercial or bank secrets can be transmitted. Generally speaking, when communicating, by phone of two people, it is assumed that their no one else hears, and the communication line is protected from listening to third parties.Unfortunately, this is not so. In TFT, electrical signals are distributed in the lines of communication in the open form.

Almost any attacker, having appropriate equipment, can access confidential information transmitted to TFP using:

Direct connection to telephone communication lines;

Contactless reading information and "bugs";

Radiation in radio and optical frequency spectra.

So how to protect speech information? Currently, two directions of protection of speech information are actively developing. One of them is associated with physical protection of telephone lines and acoustic protection of negotiations. Another telephone protection direction is based on the information conversion of telephone signals and messages.

Tools of physical protection of speech information

Masking Speech - Effective means that ensures a high degree of protection of telephone conversations. The masqueur is a noise generator, the correlation characteristics of which can dynamically change during negotiations. When passing voice information, the mask on the receiving side issues intensive noise in the telephone channel band of the telephone channel, which extends throughout the communication line, creating a strong obstacler. At the same time, the noise signal of the masqueur is used to compensate for interference in the received "mixture" of the speech signal and interference (using an adaptive filter). As a result, on the reception side, the subscriber hears a question without interference, and an attacker with interference. As a rule, the masqueur is connected from the receiving subscriber (one-sided masqueur), although it is possible to connect and on the side of the transmitting subscriber (double-sided masqueur). In the latter case, the possibility of duplex telephone conversation mode disappears, since it will take alternate and turn off each masqueur. Disadvantage when using masquerants - the presence of strong noise on the transmitting side. Unilateral speech masquerators are built into a number of devices, including: the device "Tu-man", having a level of barrier interference to 1 W in the frequency band 0.5 - 3.5 kHz; SoundPress device with noise 2 W; as well as a protective telephone module Si-2001.

Connection neutralizers The telephone line provides the creation of irreversible physicochemical transformations in the technical means that the attacker uses. The neutralizer issues a short-term signal in a line (over 1.5 kV) or a series of short pulses, which produce the destruction of the input circuits of the connected devices. Typically, the instruments of the physical destruction of unauthorized removal information devices are burned by the "bugs" on a distance of 200-300 m. Such neutralizers are BUGROASTER (bugs permanent), PTL-1500 (telephone lifeline) and "Cobra" (degree of mortgage devices). Passive protection tools are frequency filters, blocks and other devices, which, as a rule, are installed in the telephone rupture or to a telephone circuit to eliminate the possibility of listening to conversations via a telephone line in the "pen" mode. Such devices, however, do not protect the telephone line while conducting a conversation from its interception. Tools of passive protection of voice information: Corundum-M device, scattering filter MT202, telephone "bugs" MT201, LVT telephone line indicator 1007a. The means of formulations of active interference are used to protect the site "Telephone apparatus - PBX". Provide in the telephone line of the barrier interference and some change in the standard parameters of the telephone channel (for example, a telephone transmission / reception level). The interference exceeds the nominal level of the telephone signal to one or two or more orders and, acting on the input cascades and devices for the means of intercepting voice information in the communication channel, displays them from linear mode. As a result, the attacker hears instead of the desired information only noise. In order for the interference to no effect on the quality of the speech signal, it is compensated for before serving to the transmitting telephone and selected from the signals that are fed before they arrive at PBX or filter off from the useful signal. The means of formulations of active interference have the high efficiency of the protection of telephone lines from almost all types of listening devices. Among them: Electronic Mo-Dool of the integrated protection of the wired telephone line "Sprove" and "Sonata-03M", noise generators according to standard telephone lines SEL SP-17 / T, "Tsicada", "Gnome", "Proton", etc.

Telephone Line Analyzersi are designed to search for channels of intercepting telephone conversations and identify cases of unauthorized connection to the telephone line. There are two main class analyzers. The first includes devices that detect changes in the parameters of a telephone line with an unauthorized connection to it: a constant component of the current, active and reactive component of the impedance of telephone lines. Changes to these characteristics are recorded and served as a basis for making decisions about the possibility of unauthorized connection to the telephone line.

The simplest analyzers are telephone control devices CTL-2 and TPU-5 - allow you to determine the resignant changes in the line parameters and measure the voltage in them. More complex analyzers make it possible to identify an approximate sinking place to line, as well as the facts of contactless connection: analyzers of alt-01 telephone lines, AT-23, Olha, Bagem-01, MT205, search engine RT 030, cable radar "Vector" , nonlinear location systems and others. The second class is a software and hardware of radio monitoring and scanning, the principle of operation of which is based on controlling and analyzing radio emission tools for intercepting and connecting to telephone lines. Such devices make it possible to effectively identify "bugs". There are means of control - from the relatively cheap indicators of the D-006 field to universal systems for monitoring the technical channels of information for the Croon-6000 information and expensive AR-3000 scanners. The weak point of telephone lines analyzers is a high probability of false operation, as well as the inability to determine all types of connections to the telephone line.

Therefore, so-called monitoring complexes and analysis of signal control results from unauthorized access tools are created.

Such complexes can solve the following tasks:

Detection of radiation of unauthorized access tools and their localization;

Detection of side electromagnetic radiation and tip;

Evaluation of the effectiveness of the use of technical means of protection of speech information;

Monitoring the implementation of restrictions on the use of radio-electronic means;

Assessment of the species and parameters of the original information flow, which is maintained in the processed analog signal;

Maintaining a database in the parameters of signals and their sources.

Speech detection programs for voice information are installed on PEVM. They implemented most of the radio label detection algorithms. Software-hardware complexes of radio monitoring: a universal program for detecting the means of the secret removal of information "Philin", a universal monitoring program SEDIF Plus, a professional monitoring program SEDIF Pro, a system for collecting and processing data and control measurements "Regulation-P".

Recently, multifunctional devices have appeared. For example, the maintenance system of the Barrier-4 telephone line provides:

Concole of the state of the power grid and the detection of high-frequency sig-nations in it;

The ability to connect scanning and analyzing devices;

Suppression of listening and sound recording devices;

Indication of connection devices of information, etc.

Multifunctional are telephone negotiation devices From listening and writing a "Scroll" series, the complex protection of the wired line from the unauthorized removal of information "spruit", the integrated protection of the telephone line "Storm", as well as the security system of the Barrier series and others mentioned above.

Acoustic Protection Tools

To ensure the confidentiality of telephone negotiations, it is not enough to protect information in the telephone line. The likelihood of speech information is very high before transformation in the telephone tube of sound oscillations into electrical signals. Protection at this stage is called acoustic. It is based on the use of speech masking by acoustic masking noise, acting in the spectral frequency band and having a spectral characteristic. There are three main components of speech information acoustic tools. The first includes the layers of barrier acoustic interference, which are used for acoustic protection of the premises and are usually used with vibration protection equipment: "Baron", "Shore", "Storm". They allow you to protect information from interception using stethoscopes, laser microphones according to vibroacoustic distribution channels. The complex consists of a noise generator and several radio receivers, which, due to mixing, significantly reduce the likelihood of the speech signal from the noisy. The second group includes generators of acoustic noise, which are located near the place of knowledge of telephone conversations and mask the talk of the negotiation participants. At the same time, speaking in the handset is not protected from the effects of acoustic noise. Such devices include an ANG-2000 acoustic noise generator (creates an interference with a capacity of up to 2 W in a band 2 - 10 kHz). To protect against the noise of the generator, headsets of negotiation devices are used (TF-011D, OKP-6, etc.). The third group of funds are represented by acoustic masquemen: the masking noise comes from the generator simultaneously to the electro-acoustic emitter and on the input of the signal mixer, to the second input of which the signal is sent from the output of the receiving microphone. In the acoustic signal mixer, the noise component is compensated, and the cleared speech enters the telephone line. The masqueur is implemented in the acoustic protection equipment of CNDs confidential negotiations, ensures the suppression of a masking noise in the signal to a depth of 26 - 30 dB. Informational transformation of speech signals and messages The first hardware and software protection devices for speech information when it is transmitted in analog form in the telephone channel steel scramblers. With analog scrambling, the conversion of the source speech signal is made in such a way that the linear signal in the telephone line becomes illegible, although it takes the same frequency band. The speech signal may be subject to frequency inversion, frequency and temporal permutations, and in addition, the mosaic transformation (frequency inversion and temporary permutation). Analog scrambling provides only temporary resistance to speech information. In this case, under the resistance it is understood as the number of operations (transformations), which are necessary to decrypt some speech message without key knowledge. However, having a fairly powerful complex of measuring and transforming equipment, you can restore the original voice signal with acceptable quality. To increase the resistance of the speech signal conversion, cryptoblocks are introduced into the scramblers to control the scrambling. Such scramblers on the transmitting and receiving parties must ensure the synchronization of devices before starting work and maintain it during a telephone conversation. Cryptographic scrambling management leads to a signal delay, which generates the so-called echo in the telephone. The more powerful the cryptographic algorithm, the worse the quality of the speech signal on the receiving side of the telephone line. To eliminate this disadvantage, the keys of a length of about 30 bits are used for a symmetric key system and about 100 bits in the asymmetric key system. There is a large selection of a variety of scramblers: telephone / fax scramble-lera series SCR-M 1.2, "Selena", "Walnut-A", "Line-1" and other. Significantly higher resistance to speech information can be obtained when transferring it to Communication in digital form with the help of scramblers, only not analog, and digital. Encryption and decoding of speech information is carried out by one al-Gorite. The use of voice information encoders are possible when they are synchronized on the transmitting and receiving sides of the telephone channel: on the transmitting side, add to the information flow of the synchronization bits, which are highlighted on the receiving side to synchronize devices, or are used to synchronize encoders, generators of time pulses and memory synchronization schemes . An essential disadvantage of encoders is their inconsistency to the falsification of speech information. In addition, when packet switching networks appeared the ability to use block encryption to protect speech information, which compared with streaming has significant resistance. Guaranteed resistance of voice information protection can be obtained by encrypting speech codes. The digitization of the analog speech signal, compression and coding of the digital signal is carried out using the vocoder (from the English Voice Coder). The principle of operation of vocoders is based on the digitization of the speech signal by the disposable of sounds and encoding them at a small speed (1 - 2 kbps), which allows enough to prevent any sound in digital form. If a cryptographic transformation is applied to the digital stream, the encoded information of guaranteed resistance, practically unrelated decryption without knowledge of keys and the cryptoalgorithms used. Most of the vocoders and scramblers use the open distribution system of Diffi Helman cryptographic keys and the digital stream encryption based on various algorithms, including Triple Des, Cast-128, Blowfish, IDEA and Russian GOST 28147-89. The disadvantage of vocoders is some signal delay, as well as a distortion of speech information. One of the best is a codec that implements CELP algorithm that is used in a modified form in the apparatus "Referent". Commercial vocoders are relative to the road, but the number of them is growing every year: Phone Voice Coder-2400, a console to the telephone set for the protection of speech information "Nut-4130", telephone negotiation devices of the SCR-511 "Referrant". Protection of voice information In IP-telephony in IP-telephony, there are two main ways to transfer packets with voice information over the network: through the Internet and through the corporate network + dedicated channels. There are few differences between these methods, but in the second case, the best sound quality is guaranteed and a small fixed delay in voice information packets when they are transmitted via an IP network. To protect voice information transmitted in IP networks, cryptographic encryption of source packets and messages are used, which, generally speaking, make it possible to provide guaranteed IP telephony stability. There are effective cryptographic algorithms implemented on PEVM, which, when using 256-bit secret and 1024-bit open encryption keys (for example, according to GOST 28147-89), it is practically impossible to decrypt the speech package. However, when using such algorithms in IP telephony, several important factors should be taken into account that may not be reduced to many modern means of cryptographic information protection. To ensure acceptable sound quality on the receiving side when transmitting speech packets in the IP network, the delay in their delivery from the receiving side should not exceed 250 ms. To reduce the delay, the digitized speech signal is compressed, and then encrypted using streaming algorithms and transmission protocols to the IP network. Another problem of protected IP telephony is the exchange of cryptographic encryption keys between network subscribers. As a rule, the open key cryptographic protocols are used using the Diffa-Helmana protocol, which does not give someone who intercepts the conversation, to get any useful information about the keys and at the same time allows the parties to exchange information to form a common session key. This key is applied to encrypt and decipher the reflux. In order to minimize the possibility of interception of encryption keys, various subscriber and key authentication technologies are used. All cryptographic protocols and a speech stream compression protocol are selected by IP telephony programs dynamically and unnoticed by the user, providing it with a natural interface similar to the usual phone. The implementation of effective cryptographic algorithms and providing sound quality require significant computational resources. In most cases, these requirements are performed using sufficiently powerful and productive computers, which, as a rule, do not fit in the body of the telephone. But intercompatch of voice information is not always suited by IP telephony users. It is much more convenient to use a small, but better mobile IP telephony. Such devices have already appeared, although they provide the resistance of speech stream encryption are significantly lower than computer systems of IP telephony. In such telephone sets to compress the speech signal, the GSM algorithm is used, and encryption is carried out using the Wireless Transport Layer Security (WTLS) protocol, which is part of the Wireless Application Protocol protocol (WAP) implemented in mobile networks. According to experts, the future is behind such telephones: small, mobile, reliable having guaranteed resistance of speech information protection and high quality

Methods and means of protecting speech information from leakage on technical channels. Equipment and organizational measures to protect speech information. Justification of the installation of double doors and sealing the sound-absorbing material in the windows.

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Moscow Department of Education

State autonomous educational institution

secondary vocational education of the city of Moscow

Polytechnic College number 8

the name of the twice Hero of the Soviet Union I.F. Pavlova

Course project

Specialty - 090905

"Organization and technology for information protection"

bytopic:Protection of acoustic (speech) information from leakage on technical channels

Course project performed

group student: 34 Bub (C)

Lecturer: V.P. Zvereva

Moscow 2013

Introduction

1.1 Acoustic information

Chapter 4. Safety and Workplace Organization

4.1 Explanation of requirements for premises and workplaces

Conclusion

Bibliography

Introduction

According to the trends in the development of society, the most common resource is information, and, therefore, its value is constantly increasing. "Who owns information, he owns the world." This, undoubtedly, there is the essence, expressing the current situation that prevail in the world. Since the disclosure of some information often leads to negative consequences for its owner, the question of the protection of information from unauthorized production becomes becoming more acute.

Since there is a way to overcome it for each defense, then methods must be improved to ensure due secureness of information.

A worthy of attention of the attacker uses the information that the carrier of which is a speech signal or speech information. In general, speech information is a set consisting of semantic information, personal, behavioral, etc. As a rule, meaningful information is of the greatest interest.

The problem of protecting confidential negotiations is solved comprehensively with the use of various kinds of activities, including using technical means, this occurs as follows. The fact is that the primary carriers of speech information are acoustic oscillations of the air environment created by the articulatory tract of the negotiation participant. Vibrating, magnetic, electrical and electromagnetic oscillations in various frequency bands, which and "endure" confidential information from the meeting room are becoming natural or artificial ways to secondary speech information. To exclude this fact, the masking of these oscillations with similar oscillations representing the masking signals in "suspicious" or identified frequency bands. In this regard, on a permanent basis, the well-known technical channels of speech information leakage such as cable networks of various purposes, pipelines, enclosing building structures, windows and doors, side electromagnetic radiation (PEMI).

All this set of activities requires significant financial costs, both one-time (during construction or under refurbish office premises in order to fulfill information security requirements) and the current (for the above measures and to update the parking equipment park). These costs can reach several dozen, and even hundreds of thousands of dollars, depending on the importance of confidential information and financial capabilities of office space owners.

The purpose of this diploma work is theoretical and practical consideration of methods and means of protecting acoustic (speech) information from leakage on technical channels.

Tasks of this course project:

· Detection of leakage channels and unauthorized access to resources

· Technical channel leakage channels

· Tools of active protection of speech information from leakage on technical channels

The object of the study is the classification of methods and a solid for protection of speech information from leakage on technical channels

The subject of the research is organizational measures to protect speech information, the instrument of searching for intelligence funds and technical means of protecting acoustic information.

protection Acoustic Information

Chapter 1. Theoretical substantiation of methods and means of protection of speech information from leakage on technical channels

1.1 Acoustic information

The protected speech (acoustic) information includes information that is the subject of ownership and to be protected in accordance with the requirements of legal documents or the requirements established by the owner of the information. This, as a rule, information of limited access containing information related to state secrets, as well as confidential information.

To discuss information of limited access (meetings, discussions, conferences, negotiations, etc.), special premises are used (service rooms, assembly halls, conference rooms, etc.), which are called dedicated premises (VP). To prevent interception of information from these premises, as a rule, special means of protection are used, so selected rooms in some cases are called protected premises (ZP).

In the selected rooms, as a rule, auxiliary technical means and systems (WCSS) are established:

* urban automatic telephone communication;

* data transfer in the radio system;

* security and fire alarm;

* alerts and alarms;

* air conditioning;

* wired radio broadcasting and reception of broadcasting and television programs (subscriber loudspeakers, means of broadcasting, televisions and radio receivers, etc.);

* Electronic office equipment;

* electrical appliances;

* Control and measuring equipment, etc.

The isolated premises are located within the limits of the controlled zone (KZ), under which the space (territory, building, part of the building) is understood, in which the uncontrolled stay of unauthorized persons is excluded (including visitors to the organization), as well as vehicles. The boundary of the controlled zone may be the perimeter of the protected area of \u200b\u200bthe organization, the enclosing structures of the protected building or the protected part of the building, if it is posted on a unwitting territory. In some cases, the boundary of the controlled zone can be enclosing structures (walls, floor, ceiling) of the selected room.

Protection of speech (acoustic) information from leakage on technical channels is achieved by organizational and technical measures, as well as detecting portable electronic devices for intercepting information (mortgage devices) embedded in highlighted rooms.

1.2 Technical Channels Information Leakage

Acoustic canal

The acoustic channel leakage of information is implemented as follows:

· Listing conversations in open areas and indoors, being near or using directional microphones (there are parabolic, tubular or flat). The direction of 2-5 degrees, the average range of the most common - tubular is about 100 meters. With good climatic conditions in open areas, a parabolic directional microphone can work at a distance of 1 km;

· Sustainable recording of conversations on a voice recorder or tape recorder (including digital voice recorders activating by voice);

· Listening conversations using remote microphones (range of radiomycrophones 50-200 meters without repeaters).

Microphones used in radio layers can be embedded or remote and have two types: acoustic (sensitive to the action of sound oscillations of air and intended for interception of speech messages) and vibration (transformations into electrical signals of oscillations arising in a variety of hard structures).

Acoustoelectric canal

The acoustoelectric channel leakage of information whose features are:

· Ease of use (electricity is everywhere else);

· Lack of power problems at the microphone;

· The ability to remove information from the supply network without connecting to it (using the electromagnetic emission of the power supply network). Receiving information from such "bugs" is carried out by special receivers connected to the power network within a radius of up to 300 meters from the "bug" along the length of the wiring or to the power transformer serving the building or complex of buildings;

· Possible interferences on household appliances when using a power supply for information transfer, as well as poor quality of the transmitted signal with a large number of household appliances.

Prevention:

· Transformer junction is an obstacle to the further transmission of information on the power supply network;

Phone Channel

Telephone channel leakage information for listening to telephone conversations (within the framework of industrial espionage) is possible:

· Galvanic reading telephone conversations (by contacting the connecting of listening devices anywhere in the subscriber telephone network). Determined by deterioration of hearing and occurrence of interference, as well as with the help of special equipment;

· Phone-location (by high-frequency imposition). The telephone line serves a high-frequency tone, which affects nonlinear telephone elements (diodes, transistors, chips) to which acoustic signal also affects. As a result, a high-frequency modulated signal is formed in the telephone line. Detect lightning possible by the presence of a high-frequency signal in the telephone line. However, the range of such a system due to the attenuation of the RF signal in the two-wire. The line does not exceed one hundred meters. Possible opposition: suppression in the high-frequency signal in the telephone line;

· Inductive and capacitive way of unlawful removal of telephone conversations (contactless connection).

Inductive method - due to electromagnetic induction arising in the process of telephone negotiations along the wires of the telephone line. As a receiving device for information, a transformer is used, the primary winding of which covers one or two wires of the telephone line.

Capacitive method - due to the formation on the plates of the capacitor of the electrostatic field varying in accordance with the change in the level of telephone conversations. A capacitive sensor, made in the form of two plates, firmly adjacent to the telephone line, is used as a receiver of the removal of telephone conversations.

Listing the conversations in the room using telephone sets are possible in the following ways:

· Low-frequency and high-frequency method of removal of acoustic signals and telephone conversations. This method is based on connecting listening devices to the telephone line, which transformed by the microphone, sound signals are transmitted on a telephone line on a high or low frequency. Allow you to listen to the conversation in both raised and when the handset is lowered. Protection is carried out by cutting off in the high-frequency and low-frequency component telephone line;

· Using telephone remote listening devices. This method is based on the installation of a remote listening device into the elements of the subscriber telephone network by parallel to connect it to the telephone line and remotely inclusion. A remote telephone listening device has two deconpiring properties: at the time of overheard, the subscriber's telephone is disconnected from the telephone line, as well as when the handset is switched on and the telephone line power supply is incorporated with less than 20 volts, while it should be 60.

1.3 Main ways to obtain acoustic information

The main reasons for the leakage of information are:

* non-compliance with the staff of the norms, requirements, the rules of operation of the AU;

* Errors in the design of speakers and protection systems of the AC;

* Maintaining the opposing party of technical and agent intelligence.

In accordance with GOST R 50922-96, three types of leakage of information are considered:

* disclosure;

* unauthorized access to information;

* Receiving information protected by intelligence (both domestic and foreign).

Under the disclosure of the information means unauthorized budget of protected information to consumers who do not have access to protected information.

Under unauthorized access, it is understood to obtain a protected information by an interested subject with a violation of the legal documents established by legal documents or the owner, the owner of the rights information or the rules of access to protected information. At the same time, a stakeholder carrying out unauthorized access to information may be: a state, legal entity, a group of individuals, including a public organization, a separate individual.

Obtaining information protected by intelligence can be carried out using technical means (technical reconnaissance) or agent methods (agent intelligence).

Composition of information leakage channels

Source of Kui.	Name of Kui.	Description
Telephone lines Radiotelephone	Electroacoustic, pemin
Urban and local radio broadcast	Electroacoustic, pemin	Information leakage due to acoustoelectric transformation in the receiver line of radio broadcasts; Information leak due to the modulation by the useful signal of the EM fields formed during the operation of household appliances.
PEVM with full configuration		Information leak due to the modulation by the useful signal of the EM fields formed during the operation of household appliances.
Photo optical detectors	Electroacoustic, pemin	Information leakage due to acoustoelectric transformation in the receiver line of radio broadcasts; Information leak due to the modulation by the useful signal of the EM fields formed during the operation of household appliances.
Heating and ventilation system	Acoustic	Information leakage due to weak acoustic isolation (slots, no densities, holes). These non-dednts can be attributed: - cracks near the mortgage pipes of the cables, - ventilation, not the density of the door and the door frame. Transferring information by vibration through heating risers.
Power supply system	Electroacoustic, pemin	Information leakage due to acoustoelectric transformation in the receiver line of radio broadcasts; Information leak due to the modulation by the useful signal of the EM fields formed during the operation of household appliances.
3G Mobile Phone	Acoustic	Draft information on radio channel.
Ceiling overlaps	Acoustic	The membrane transfer of the energy of speech signals through partitions due to the low mass and weak signal attenuation.
	Vibrating	Information leakage by removing the useful signal from vibrating when conversing surfaces.
Grounding system	Electroacistic	Draft information due to acoustoelectric conversion in the receiver line of the radio broadcast.

Of all possible channels of information leakage, the most attractiveness for attackers are the technical channels of information leakage, to organize hide and protection against information leakage, it is necessary first of all through these channels. Since the organization of hiding and protecting acoustic information from leakage on technical channels The event is quite expensive, it is necessary to carry out a detailed study of all channels, and it is impossible to apply the technical means of protection in those places where it is impossible without them.

Chapter 2. Practical substantiation of methods and means of protecting speech information from leakage on technical channels

2.1 Organizational Speech Information Protection Activities

The main organizational activities to protect speech information from leakage on technical channels include:

* Selection of premises for confidential negotiations (selected premises);

* Use of certified auxiliary technical means and systems (WCS);

* establishing a controlled zone around the VP;

* dismantling in VTCS unused VTCS, their connecting lines and foreign conductors;

* organization of the mode and control of access to the VP;

* Disabling bringing confidential negotiations of unprotected VTCS.

Premises in which confidential negotiations are assumed should be chosen by their sound insulation, as well as the opponents of the enemy to intercept speech information on acustomibration and acousto-optic channels. As allocated, it is advisable to choose premises that do not have common enclosing designs with rooms belonging to other organizations, or with rooms in which there are uncontrolled access to unauthorized persons. By the possibilities of the window of the selected premises should not go to the parking lots of the parking lot, as well as nearby buildings, of which intelligence is possible using laser acoustic systems.

In the event that the boundary of the controlled zone are enclosing designs (walls, gender, ceiling) of the selected room, a temporary controlled zone may be established for the period of confidential activities, which excludes or significantly impede the possibility of intercepting speech information.

In the selected rooms, only certified technical means and systems should be used, i.e. Special technical inspections for the possible presence of embedded mortgage devices, special studies for the presence of acoustoelectric channel leakage channels and having certificates of compliance with information security requirements in accordance with regulatory documents of FSTEC of Russia.

All unsupported auxiliary technical means for confidential negotiations, as well as foreign cables and wires passing through the selected room, must be dismantled.

Unattended technical means established in highlighted premises, when conducting confidential negotiations, should be disconnected from connecting lines and power sources.

Dedicated premises in the extramanent time should be closed, sealed and surrendered. In the service time, employees access to these premises should be limited (by lists) and monitor (visiting accounting). If necessary, these premises can be equipped with access control and access control systems.

All work on the protection of PP (on the stages of design, construction or reconstruction, installation of equipment and equipment for information protection, VP certification) are carried out by organizations that have a license to protect information.

When entering the EMP, and then it must be certified according to the safety requirements of information in accordance with the regulatory documents of the FSTEC of Russia. Periodically, its special examination should be carried out.

In most cases, only organizational activities fail to provide the required information protection efficiency and it is necessary to conduct technical information protection activities. The technical event is an event to protect information providing for the use of special technical means, as well as the implementation of technical solutions. Technical measures are aimed at closing the channel leakage channels by reducing the signal-to-noise ratio in the places of possible placement of portable acoustic exploration tools or their sensors to magnitude that ensures the impossibility of exchanging the information signal tool. Depending on the funds used, technical methods of protecting information are divided into passive and active.

Passive information protection methods are aimed at:

· Weakening acoustic and vibration signals up to magnitudes that ensure the impossibility of their allocation of acoustic intelligence in the background of natural noise in the places of their possible installation;

· Weakening of information electrical signals in connecting lines of auxiliary technical means and systems arising from acoustically electrical transformations of acoustic signals up to values \u200b\u200bthat ensure the impossibility of their selection by means of intelligence against the background of natural noise;

· Exception (weakening) of the passage of high-frequency imposition signals in VTCS, which have electrical transducers in their composition (with microphone effect);

· Weakening radio signals transmitted by mortgage devices to values \u200b\u200bthat ensure the impossibility of receiving them in the locations of the possible installation of receiving devices;

· Weakening of signals transmitted by mortgage devices 220 V, up to values \u200b\u200bthat ensure the impossibility of receiving them in places possible installation of receiving devices

Fig. 1 Classification of passive protection methods

The weakening of speech (acoustic) signals is carried out by sound insulation of rooms, which is aimed at localization of sources of acoustic signals within them.

Special inserts and gaskets are used for the vibration junction of pipes of heat, gas, water supply and sewage, leaving the controlled zone

Fig.2. Installation of special means

In order to close the acoustoelectromagnetic channels of the leakage of voice information, as well as the channel leakage channels created by the hidden installation in the premises of the mortgage devices with the transfer of radio channel information, various ways of shielding selected rooms are used.

Installing special low-frequency filters and limiters in the BTCS connecting lines that go beyond the controlled zone are used to eliminate the ability to intercept speech information from selected rooms by passive and active acoustoelectric information leakage channels

Special FP-type low-frequency filters are installed in the power supply lines (socket and lighting network) of the selected room in order to exclude possible transmission on them, intercepted by network bookmarks (Fig. 4). For these purposes, filters are used with the FGP boundary frequency? 20 ... 40 kHz and a weakening of at least 60 - 80 dB. Filters must be installed within the controlled zone.

Fig.3. Installing a special device - Granite-8

Fig. 4. Installing special filters (type FP).

In the case of the technical impossibility of using passive facilities for the protection of premises or if they do not provide the required sound insulation standards, active methods for protecting speech information that are directed to:

· Creation of masking acoustic and vibratory noise in order to reduce the signal-to-noise ratio to values \u200b\u200bthat ensure the impossibility of the use of speech information acoustic intelligence in the places of their possible installation;

· Creation of masking electromagnetic interference in the WCSS connecting lines in order to reduce the signal-to-noise ratio to values \u200b\u200bthat ensure the impossibility of exchanging the information signal to the intelligence means in possible places of their connection;

· Suppression of recording devices (voice recorders) in recording mode;

· Suppression of receiving devices that receive information from the inclined devices by radio channel;

· Suppression of receiving devices that make information from deployed electrical power supply devices 220 V

Fig.5. Classification of active protection methods

Acoustic disguise is effectively used to protect voice information from leakage along the direct acoustic channel by suppressing acoustic interference (noise) microphones of the intelligence means, installed in such elements of the designs of protected areas, like a door tambour, ventilation channel, suspended ceiling space, etc.

Vibroacoustic disguise is used to protect speech information from leakage acustibration (Fig. 6) and acousto-optic (optical-electronic) channels (Fig. 7) and consists in creating vibration noise in elements of building structures, window glass, engineering communications, etc. Vibroacoustic disguise is effectively used to suppress electronic and radio networks, as well as laser acoustic intelligence systems

Fig. 6. Creation of vibratory interference

Creating masking electromagnetic low-frequency interference (low-frequency disguise interference method) Used to eliminate the possibility of intercepting voice information from selected premises for passive and active acoustoelectric information leakage channels, suppressing wired microphone systems using CTCS connecting lines for low frequency information and suppressing acoustic bookmarks Type "phone ear".

Most often, this method is used to protect telephones that have elements with the "microphone effect" in its composition, and is to be submitted to a line when the masking handset is supplied (most often - the type of "white noise") of the speech frequency range (usually , The main power of the interference is focused in the range of frequencies of the standard telephone channel: 300 - 3400 Hz) (Fig. 8).

Fig. 7. Creating noise

Creating masking high-frequency (frequency range from 20-40 kHz to 10-30 MHz) electromagnetic interference in the power supply lines (socket and lighting network) of the selected room is used to suppress information reception devices from network bookmarks (Fig. 9).

Creating spatial masking high-frequency (frequency range from 20-50 kHz to 1.5 - 2.5 MHz) * Electromagnetic interference is mainly used to suppress information devices from radio layers (Fig. 10).

Fig. 8. Creating high-frequency interference

Soundproofing of rooms

Soundproofing (vibration insulation) of selected (protected) premises (VP) is the main passive method of protecting voice information and is aimed at localizing sources of acoustic signals inside them. It is held to eliminate the possibility of listening to conversations in the allocated premises, as without the use of technical means to unauthorized persons (visitors, technical personnel), as well as employees of an organization that are not admitted to the information discussed, when they are found in corridors and related to the dedicated premises ( unintended listening) and an opponent for direct acoustic (through slots, windows, doors, technological openings, ventilation channels, etc.), sharkist (through fencing structures, engineering communications pipes, etc.) and acousto-optic (through window Glass) Technical Channels for leakage of information using portable tools acoustic (speech) intelligence.

As an indicator of assessing the effectiveness of the sound insulation of the selected rooms, the verbal intelligibility of speech, characterized by the number of properly understood words and reflecting the qualitative area of \u200b\u200bunderstandability, which is expressed in the categories of details of the certificate of the certificate taken with the help of technical means of intelligence conversation.

The process of perception of speech in noise is accompanied by losses of composite elements of the speech message. In this case, the intelligibility of speech will be determined not only by the level of speech signal, but also the level, as well as the nature of the external noise at the place of placement of the sensor of the intelligence means.

The criteria for the effectiveness of speech information are largely dependent on the goals pursued by the organization of protection, for example: to hide the semantic content of the leading conversation, hide the theme of the leading conversation or to hide the very fact of negotiations.

Practical experience shows that the compilation of a detailed certificate of the content of the intercepted conversation is impossible with verbal intelligibility less than 60 - 70%, and a brief reference-annotation - with verbal intelligibility less than 40-60%. With verbal intelligibility less than 20 - 40%, the establishment of even the subject of the leading conversation is significantly difficult, and with verbal intelligibility less than 10 - 20%, it is almost impossible even when using modern methods of noise cleaning.

Considering that the level of the speech signal in the dedicated room can be from 64 to 84 dB, depending on the level of acoustic noise at the location of the intelligence means and the selected room, it is easy to calculate the required level of sound insulation to ensure effective protection of speech information from leakage for all possible technical canals.

Soundproofing of premises is provided with the help of architectural and engineering solutions, as well as the use of special construction and finishing materials.

When the acoustic wave falls on the boundary of surfaces with various specific densities, most of the incident wave is reflected. A smaller part of the wave penetrates the material of the soundproofing design and distributes in it, losing its energy depending on the path length and its acoustic properties. Under the action of acoustic wave, the soundproofing surface performs complex oscillations, also absorbing the incident wave energy.

The nature of this absorption is determined by the ratio of the frequencies of the incident acoustic wave and the spectral characteristics of the surface of the sound insulation.

When assessing the soundproofing of the selected rooms, it is necessary to consider sound insulation: enclosing room structures (walls, floor, ceiling, windows, doors) and engineering systems (supply and exhaust ventilation, heating, air conditioning).

2.2 Equipment for the search for technical means of intelligence

Multifunctional search device ST 033 "Piranha"

ST 033 "Piranha" is intended for operational measures to detect and localize technical means of tight information, as well as to identify natural and artificially created channel leakage channels.

The product consists of the main control unit and indication, the set of converters and allows you to work in the following modes:

· High-frequency detector frequency meter;

· Microwave detector (together with ST03.SHF)

· Wired lines analyzer;

· IR radiation detector;

· Low-frequency magnetic field detectors;

· Differential low-frequency amplifier (together with ST 03.DA);

· Vibroacoustic receiver;

· Acoustic receiver

Figure 9 - Multifunctional search device ST 033 "Piranha"

The transition to any of the modes is automatically carried out when the corresponding converter is connected. The information is displayed on the graphic LCD display with backlight, acoustic control is carried out through special headphones, or through the built-in loudspeaker.

It is possible to memorize in high-dependent memory to 99 images.

There is an indication of incoming low-frequency signals in the oscilloscope modes or a spectrum analyzer with an indication of numerical parameters.

In ST 033, "Piranha" is provided with a contextual displays depending on the operation mode. Possible a choice of Russian or English.

ST 033 "Piranha" is made in the wearable version. For its carrying and storage, a special bag is used, adapted for compact and convenient laying of all elements of the kit.

Using ST 033 "Piranha" Perhaps the following control and search tasks:

1. Detection of the fact of work (detection) and localization of the location of radio emission special technical means creating potentially dangerous, from the point of view of information leakage, radio emission. To such means, first of all, include:

· Radio microphones;

· Telephone radio places;

· RadioToscopes;

· Hidden camcorders with radio channel transmission radio channel;

· Technical means of spatial high-frequency irradiation systems in the radio view;

· Radiomaica of tracking systems for moving objects (people, vehicles, cargo, etc.);

· Unauthorized Cell Phones GSM, DECT standards, radio stations, radiotelephones.

· Devices using data channel data transmission using Bluetooth and WLAN standards.

2. Detection and localization of the location of special technical means working with radiation in the infrared range. To such means, first of all, include:

· Enchanting devices for the extraction of acoustic information from the premises with its subsequent transmission over the channel in the infrared range;

· Technical means of spatial irradiation systems in the infrared range.

3. Detection and localization of the location of special technical means used to mining and transmitting information wired lines of various purposes, as well as technical means of processing information that create an informative signals on a nearby wired lines or dragging these signals in the power supply line. Such means can be:

· Embedded devices that are used to transmit the intercepted information of the AC 220V network line and capable of working at frequencies to 15 MHz;

· PEVM and other technical means of manufacturing, reproduction and information transfer;

· Technical means of linear high-frequency imposition systems operating at frequencies of over 150kHz;

· Fitting devices that use subscriber telephone lines for transmission of intercepted information, lines of fire and security alarm systems with a carrier frequency of more than 20 kHz.

4. Detection and localization of the location of sources of electromagnetic fields with a predominance (presence) of the magnetic component of the field, the tracks of the hidden (unsubshot) electrical wiring, potentially suitable for the installation of mortgage devices, as well as a study of technical means processing voice information. To the number of such sources and technical means it is customary:

· Output transformers of sound frequency amplifiers;

· Dynamic speakers of acoustic systems;

· Electric motors of tape recorders and voice recorders;

5. Detection of the most vulnerable places, from the point of view of the occurrence of vibroacoustic channel leakage channels.

6. Detection of the most vulnerable places, from the point of view of the occurrence of channels of acoustic information leakage.

Mode of vibroacoustic receiving

In this mode, the product provides a reception from an external vibrationacoustic sensor and mapping low-frequency signals in the range from 300 to 6000 Hz.

The state of vibroacoustic protection of the premises is estimated both quantitatively and efficiently.

Quantitative estimate of the protection status is carried out on the basis of the analysis automatically displayed on the screen display screen, which displays the shape of the received signal and the current value of its amplitude.

A qualitative assessment assessment is based on direct listening to the adopted low-frequency signal and the analysis of its volume and timbre characteristics. This uses either a built-in loudspeaker, or headphones.

Specifications

The mode of acoustic receiver

In this mode, the product provides a reception to an external remote microphone and the display of the parameters of the acoustic signals in the range from 300 to 6000 Hz.

The condition of sound insulation of the premises and the presence of vulnerable in them, from the point of view of information leakage, places are defined both quantitatively and qualitatively.

Quantitatively Assessing the Soundproofing Status of the Rooms and the detection of possible channel leakage channels are carried out on the basis of the analysis automatically displayed on the display screen of the oscillogram reflecting the form of the received signal and the current value of its amplitude.

A qualitative assessment is based on direct listening to the acoustic signal and the analysis of its volume and timbre characteristics. This uses either a built-in loudspeaker, or headphones.

Specifications

General specifications ST 033 "Piranha"

High Frequency Freight Detector
Range of operating frequencies, MHz
Sensitivity, MV.	< 2 (200МГц-1000МГц) 4 (1000 MHz-1600 MHz) 8 (1600 MHz-2000 MHz)
Dynamic range, dB
Sensitivity of the frequency meter, mV	<15 (100МГц-1200МГц)
Accuracy of frequency measurement,%
Scanning Wired Lines Analyzer
Scan Range, MHz
Sensitivity, with C / W 10 dB, MV
Scan step, kHz
Scan speed, kHz
Bandwidth, kHz
Selectivity on the neighboring channel, dB
Detection mode
Permissible voltage in the network, in
Detector IR radiation
Spectromic Range, Nm
Threshold sensitivity, W / Hz2
The angle of sight, hail.
Frequency band, MHz
Magnetic Litch Detector
Frequency range, kHz
Threshold sensitivity, a / (m x Hz2)
Vibroacoustic receiver
Sensitivity in x x2 / m
Own noise in the 300Gz-3000Hz strip, MKV
Acoustic receiver
Sensitivity, MV / Pa
Frequency range, Hz
Oscilloscope and spectrum analyzer
Bandwidth, kHz
Sensitivity at the entrance, MV
Measurement error,%
Output rate of oscillogram, with
Spectrogram output rate, with
Indication
LCD graphic display with a resolution of 128x64 with adjustable illumination
Supply voltage, in	6 (4 batteries or batteries of AA) / 220
Maximum current consumption, no more, ma
Current current in working mode, no more, ma
Gabarites, mm.
Main block
Bag packaging
Main block

Completeness of delivery

Name	Number, pcs
1. Main control unit, processing and indication
2. Active RF Antenna
3. The adapter of the scanning analyzer of wired lines
4. Nozzle type "220"
5. Nozzle type "Crocodile"
6. Nozzle type "needle"
7. Magnetic sensor
8. IR sensor
9. Acoustic sensor
10. Vibroacoustic sensor
11. Telescopic antenna
12. Headphones
13. Element of type AA
14. Shoulder strap
15. Stand of the main unit
16. Power supply
17. Bag - Packaging
18. Technical description and instruction manual

2.3 Technical means of protecting acoustic information from leakage on technical channels

Spatial nois generators

Noise Generator Thunder-Zi-4 is designed to protect premises from information leakage and prevent information from personal computers and local computing networks based on PCs. Noise-generator Universal range of 20 - 1000 MHz. Modes of operation: "Radio channel", "Telephone line", "Electrose"

The main functionality of the device:

· Generation of interference by ether, telephone line and power grid to block unauthorized installed devices transmitting information;

· Disguise by side electromagnetic radiation PC and LAN;

· No need to adjust specific conditions for use.

Noise Generator "Thunder-Zi-4"

Technical data and characteristics of the generator

· The intensity of the interference field generated by the ether relative to 1MKV / M

· The voltage of the signal generated by the electrical network relative to 1 μV in the frequency range of 0.1-1 MHz is at least 60 dB;

· Signal generated by telephone line - pulses with a frequency of 20 kHz amplitude 10V;

· Power supply from 220V 50Hz power supply.

Generator Thunder 3I-4 is part of the Thunder 3-4 system together with a disconcile antenna Si-5002.1

Si-5002.1 disconcile antenna parameters:

· Operating frequency range: 1 - 2000 MHz.

· Vertical polarization.

· Food diagram - quasicarround.

· Dimensions: 360x950 mm.

Antenna can be used as a receiving antenna in the composition of radiocontrol complexes and in the study of the tension of noise and pulsed electric fields of radio signals with measuring receivers and spectrum analyzers

Telephone Line Protection Equipment

"Lightning"

"Lightning" is a means of protection against unauthorized listening of negotiations both by telephone and indoors with devices running in wired lines or power supply lines.

The principle of the operation of the device is based on the electric test of radio elements. When you click on the "Start" button, a powerful short high-voltage pulse is supplied, capable of completely destroying or disrupting the functional activity of means of removal of information.

Device protection against leakage acoustic channels "Troyan"

Troyan Acoustic block of all devices for eating information.

In the conditions of the appearance of increasingly perfect devices for the rehistribution of voice information, the use of which is difficult to fix the search engineering (laser devices of the reservoir, stethoscopes, directional microphones, microphone microphone radiomycrophones, wire microphones, modern digital voice recorders, radio label, transmitting acoustic information on the electrical network and Other lines of communication and alarm at low frequencies, etc.), the acoustic masqueur often remains the only means that ensures the guaranteed closure of all channels of voice information leakage.

Principle of operation:

In the conversation zone there is a device with remote microphones (microphones must be at a distance of at least 40-50 cm. From the instrument to avoid acoustic feedback). During the conversation, the speech signal comes from microphones on the electron processing scheme, which eliminates the phenomenon of acoustic feedback (microphone - speaker) and turns it to a signal that contains the basic spectral components of the original speech signal.

The device has an acoustope circuit with an adjustable inclusion threshold. The acoustope system (VAS) reduces the duration of the impact of speech interference by rumor, which helps to reduce the effect of fatigue from the effect of the instrument. In addition, the operation time of the device from the battery is increasing. The recyclable interference of the device sounds synchronously with the masked speech and its volume depends on the volume of the conversation.

Small dimensions and universal food allow you to use the product in the office, car and in any other unprepared place.

In the office to the device, you can connect computer active speakers for increasing the large area, if necessary.

Main technical characteristics

Type of generated interference	rech-like, correlated by the original speech signal. The intensity of the interference and its spectral composition is close to the original speech signal. Each time the device is turned on, non-refined fragments of the rico-like interference
Range of reproducible acoustic frequencies
Device control	with two external microphones
Output power amplifier audio frequency
Maximum sound pressure from the internal loudspeaker
The voltage of the interference signal on the linear output depends on the position of the volume controller and reaches the value
Food products	from the rechargeable battery, 7.4 V. charge the battery from the power supply 220 V using the adapter, which is included in the product kit.
Battery full charge
Capacity used battery
The time of continuous operation when powered by a fully charged battery depends on the volume of the sound and is	5 - 6 hours
Maximum current consumed at full volume
Dimensions of the product	145 x 85 x 25 mm

Equipment:

· Main block,

· Network adapter charging,

· Passport on the product with instruction manual,

· Extension for computer speakers

· Removeless amicrophones.

Suppressant "Canonir-K" microphone listening devices

The product "Canonir-K" is intended to protect the place of negotiations from the means of auxiliary acoustic information.

Radio microphones, wired microphones and most digital voice recorders, including voice recorders in mobile phones (smartphones) are blocked in silent mode. The product in silent mode blocks the acoustic channels of mobile phones, which have near the device from emitters. Locking microphones of mobile phones does not depend on the standard of their work: (GSM, 3G, 4G, CDMA, etc.) and does not affect the reception of incoming calls.

When blocking a variety of means of eating and recording speech information in the product, both rico-like and silent ultrasonic interference.

In the routine interference mode, all available means of a meal and recording acoustic information are blocked.

A brief overview of the dictaphones and radio microphones available on the market:

· Microwave blocks: (storm), (desigrating), etc.

Dignity is a silent mode of operation. Disadvantages: Do not block the work of voice recorders in mobile phones and most modern digital dictaphones

· Generators of rico-like signals: (Fakir, Shaman), etc.

Effective only when the volume of the conversation does not exceed the level of acoustic interference. The conversation has to be conducted with loud noise, which is tiring.

· Products (comfort and chaos).

The devices are very effective, but the conversation has to be conducted in tightly adjacent microthephon headsets, which is not acceptable for everyone.

The main technical characteristics of the Canonir-K product.

Power: Rechargeable battery (15V. 1600mA.) (If the red LED goes out, you need to connect the charger). When the charging device is connected, a green LED is burned near the outlet slot. If the LED is burning dim or goes out, it indicates a full battery charge. Brightly burning LED indicates a discharged battery.

· The battery full charge is 8 hours.

· Current consumption in silent mode - 100 - 130 mA. In the mode of rico-like interference together with a silent regime - 280 mA.

· Signal voltage of the speech-like interference at a linear output - 1B.

· The time of continuous operation in two modes at the same time - 5 hours.

· Blocking range of radio microphones and voice recorders - 2 - 4 meters.

· The angle of radiation of ultrasonic interference is 80 degrees.

· Dimensions of the product "canonir-k" - 170 x 85 x 35 mm.

In the second chapter, organizational measures to protect speech information were considered, the equipment for the search for technical means of intelligence, technical means of protecting acoustic information from leakage on technical channels. Since the use of technical means of protecting the occupation is expensive, these funds will have to use not throughout the entire pyrimmeter of the room, but only in the most vulnerable places. The instructional instrument for the search for technical means of intelligence and the means of active protection of information from leakage on vibroacoustic and acoustic channels was considered. Since in addition to the technical channels of information leakage, there are also other ways to theft of information, applying data technical means needed together with technical means of protecting information on other possible channels.

Chapter 3. Technical and Economic Justification

In this diploma project, the composition of material costs can be determined taking into account certain features relating to the installation of acoustic and vibro-acoustic protection system. In this case, since the work happens on the spot, shops and public expenditures must be combined under a single cost name. As source information, formula 2 can be used as source information to determine the sum of all costs.

Sat.k. \u003d M + OZP + DZP + ESN + CO + OKH + KZ

where M - the cost of materials;

OZO is the main salary to specialists involved in the development of the program;

DZP is an additional salary to specialists involved in the development of the program;

Esn - a single social tax;

CO - the costs associated with the operation of the equipment (depreciation);

OKR - generality costs;

KZ - extraproductive (commercial) costs.

Calculation of financial costs is calculated taking into account the route maps presented in Table 9.

Operating time

In the installation process, such equipment as a perforator, crimp tool, tester were used. The table indicates the consumables and equipment necessary to create a network.

Vibro-acoustic protection equipment (Vibro-acoustic noise generator "LGSh - 404" and emitters to it in an amount of 8 pcs) and the suppressor of microphone listening devices "canonir-K" is purchased by the Customer and are not counted in the calculation of material costs.

Cost statement

Name Materials	unit of measurement	Price per unit measurement, rub.	number	Amount, rub.
4. Selfness
6. The drill is winning
8. Roulette
11. Crossing screwdriver

The volume of material costs on the product M, rub is calculated by formula 3

M \u003d u pi · qi

where Pi is the form of the I material in line with the quantity;

qi - the value of the specific unit I of the material.

Calculation of material costs is calculated by the formula

M \u003d 2 + 5 + 30 + 50 + 200 + 100 \u003d 387 (rub.)

The calculation of the main wage is carried out on the basis of the developed technological process of work, which should include information:

About the sequence and content of all the work performed,

On the qualifications of workers involved in the performance of certain types of work at all production stages (transitions, operations),

On the complexity of the implementation of all types of work,

On the technical equipment of jobs when performing work at all its stages.

Since some preferential categories of employees and planned prizes for established tariffs for high-quality and timely execution of work can participate in the formation of the basic wage fund in the formation of a high-quality and timely performance of work; corrective coefficients are provided. Their values \u200b\u200bare determined on the basis of increasing interest rates relative to the direct costs of salary payroll. Increased interest rates are recommended to choose from 20% to 40% in the range, in this work it is selected based on interest rate of 30%, or KPP \u003d 0.3.

To determine the financial costs, it is necessary to attract an employee to the relevant qualification for which the monthly salaries must be determined. The salary of the employee for similar work is 50,000 rubles per month, based on this we define the hourly tariff rate of Ocholya rubles per hour by the formula

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Subsections:

Using an IR range to remove information from window glass and a protection circuit - page 16

5. Frequency muffler as a means of protection against wiretapping. - P.23.

Removing information from glass and fighting it

Laser acoustic intelligence

In recent years, there has been information that the special services of various countries for unauthorized receipt of speech information are increasingly using remote ports of acoustic intelligence.

The most modern and efficient is the acoustic intelligence laser, which allow you to reproduce speech, any other sounds and acoustic noises with laser-local sounding of window glass and other reflective surfaces.

To date, a whole family of acoustic reconnaissance laser remedies has been created. As an example, you can cite the SIPE LASER 3-DA Super system. This model consists of the following components:

Radiation source (helium neon laser);

Receiver of this radiation with noise filtering unit;

Two pairs of headphones;

Power battery and tripod.

This system works so. The laying of laser radiation on the window glass of the desired room is carried out using a telescopic vizier. Change the separation angle of the emerging, the beam allows an optical nozzle, the high stability of the parameters is achieved through the use of the automatic control system. The model provides speech information from window frames with double glasses with good quality up to 250 m.

Physical bases of speech interception by laser microphones

Consider briefly physical processes occurring while intercepting speech using a laser microphone. The probed object is usually the window glass - is a kind of membrane that fluctuates with sound frequency, creating a ringing phonogram.

The radiation generated by the laser transmitter, spreading in the atmosphere, is reflected from the surface of the window glass and is modulated by an acoustic signal, and then perceived by a photodetector, which restores the reconnaissance signal.

In this technology, the modulation process is fundamental. A sound wave generated by the source of an acoustic signal drops on the boundary of the air-glass section and creates a kind of vibration, that is, the deviations of the glass surface from the source position. These deviations cause reflected from the border.

If the dimensions of the incident optical beam are small compared with the length of the "surface" wave, then in the superposition of various components of the reflected light will dominate the diffraction bundle of zero order:

First, the light wave phase turns out to be industrialized with a frequency of sound and homogeneous by a beam cross section;

Secondly, the bundle "swinging" with the frequency of sound around the direction of the mirror reflection.

The following factors influence the quality of information:

The parameters of the laser used (wavelength, power, coherence, etc.);

Parameters of the photodetector (sensitivity and selectivity of the photodetector, type of processing of the received signal, etc.);

The presence on the windows of the protective film;

Note.

When the layer of protective and layer of the tinting film is significantly reduced, the level of glass vibration caused by acoustic (sound) waves is significantly reduced. It is difficult to fix the glass fluctuations outside, so it is difficult to highlight the beep in the adopted laser radiation.

Atmospheric parameters (scattering, absorption, turbulence, background illumination level, etc.);

The quality of the treatment of the probed surface (roughness and irregularity due to both technological causes and the impact of the medium - dirt, scratches);

Level of background acoustic noise;

The level of the intercepted speech signal; Specific local conditions.

Note

All these circumstances impose their mark on the quality of the recorded speech, so it is impossible to take on the faith to receive data from a distance of hundreds of meters - these numbers are obtained under conditions of the polygon, or even calculated path.

Of the foregoing, you can do the following

Laser removal systems exist and are in competent operation a very effective means of obtaining information;

Laser microphones are not a versatile agent, as much depends on the conditions of application;

Not all is a laser intelligence system, which is so called the seller or manufacturer;

Without qualified personnel, thousands and even tens of thousands of dollars spent on the acquisition of a laser microphone will disappear;

Security services should reasonably assess the need to protect information from laser microphones.

The principle of operation of the laser microphone is presented on 6.1.

Note

We all know the law of physics - "the angle of the fall is equal to the corner of the reflection." This means that it is necessary to be strictly perpendicular to the window of the listened room. From the apartment opposite you are unlikely to catch the reflected ray, as the walls of the building usually, I'm not talking about the windows, a little curved and reflected ray will pass by.

Before an important meeting, we open the window, and so far spies run on neighboring buildings and are looking for a reflected beam, you will certainly have time to discuss all the important points, and if you change the position of the window every 5-10 min. (Opening, close), then all the desire to listen to you after such a marathon will pass.

The problem of countering any information using laser radiation remains very relevant and at the same time, one of the least studied compared to other, less "exotic" means of industrial espionage.

Note.

The sensitivity of the device can be enhanced by additional IR LEDs, parallel to the transmitter VD1 (through its restrictive resistors). You can also increase the receiver gain, adding a cascade similar to Cascade at A1.2. To do this, you can use free OU microcircuit A1.

Structurally, the LED and photodiode is located so as to exclude the direct hit of the IR radiation of the LED onto the photodiode, but confidently take reflected radiation.

The receiver is powered by two kroon type batteries, the transmitter is powered by four elements of type R20 with a total voltage of 6 V (1.5 V each).

In infrared devices with transmission and reception of the beam, the receiver and transmitter are taken to perform, although in most cases they, at least, have a common power source, and then are located next to each other (http://microcopied.ru/content/View/475/ 25 / L / 0 /).

Therefore, if two wires going to the receiver from a common power source transmitter, add only one synchronization wire, you can get a wonderful device. It will work on the principle of a synchronous detector and have its properties as: selectivity; noise immunity; The ability to get a big gain.

And this is without the use of multi-stage amplifiers with complicated filters.

Inside the room, even without the use of additional optics and powerful emitters, the device can be used as a security alarm, triggered when crossing the infrared beam at a distance from the emitter to the receiver 3-7 m.

Moreover, the device does not respond to the external illumination from foreign sources, both permanent (sun, incandescent lamps) and modulated (fluorescent lighting, flashlight).

By equipping the receiver's LED, you can overlap several dozen distance meters in the open space, having excellent noise immunity even with a rude snow. When using lenses on the receiver and transmitter, it is simultaneously overlapping even more distance, but the problem of accurate guidance of the narrow beam of the transmitter on the receiver lens occurs.

Transmitter generator Signed on the DA1 integral timer included according to the multivibrator scheme. The multivibrator frequency is selected in the range of 20-40 kHz, but maybe anyone. It is only limited to the bottom of the C7, C7 capacitors, and from above the frequency properties of the timer.

The multivibrator signal via the VT5 key controls the VD2-VD4 transmitter LEDs. The radiation power of the transmitter can be selected by changing the number of LEDs or current through them resistor R17. Since diodes work in a pulse mode, the amplitude value of the current through them can be twice as high above the permanently permissible.

Transmitter scheme

made on discrete elements VD1, VT1-VT4, R1-R12, according to the scheme used in many Soviet TVs. Its successfully can be replaced by an imported integrated IR receiver having an infrared light filter. However, it is desirable that a digital signal is not formed at the receiver output, that is, its tract would be linear.

Next, the enhanced signal enters the DD1 multiplexer made on the CMOS and the DA1 timer controlled. At the outputs of 3.13 DD1 there is a useful antiphase signal that is enhanced by the differential integrator to the DA2 OU. Elements R19, R20; C10, C11; The integrator R21, R22 determine the signal amplification level, the receiver bandwidth and response speed.

Note.

The level of "land" of the integrator is determined by the VD5 stabitron, and is selected as smaller as possible (but so that the DA2 is not included in the limit), since the useful signal at the DA2 output will be positive.

The Schmitt trigger is performed on the DA3. Together with the peak detector on the elements R24, VD6, R25, C12, it performs the role of a comparator for generating a response signal. The voltage drop on the VD6 diode reduces the peak voltage level of 0.4-0.5 V. This sets the "floating" alarm threshold, the value of which smoothly changes depending on the distance between the receiver and the transmitter, the level of the illumination, interference. With the normal passage of the beam, the VD7 LED will light up, when crossing the beam, the LED goes out.

It is not available in the scheme, there are no special requirements. Elements can be replaced with similar imported or domestic. The R25 resistor is composed of two consecutive 5.1 hours. The VD1 photodiode with the amplifier must necessarily be placed in a metal grounded screen to prevent pressing.

The setup scheme does not require, but should be attentive when testing the device. The transmitter signal can fall into the receiver as a result of reflection from nearby objects and will not give to see the result of the functioning of the scheme. It is most convenient for debugging to reduce the current of the radiator LEDs to the fraction of Milliamper.

To operate the device as an IR alarm, you can connect the indication unit to the device to the device. The SA2 switch is selected the mode of operation of the indication block. In the position "Single" with the crossing of the beam, one beep is formed by a duration of 1 seconds. In the "Constant" position, the beep sounds constantly until the block is reset with the SA1 button.

In addition to the operation of the device in mode, when the emitter is directed to the receiver, you can direct them in one direction (of course, eliminating the direct hit of the transmitter beam to the receiver).

Thus, the IR locator scheme will be implemented (for example, for the car parking sensor). If you provide an IR transmitter and receiver collecting lenses and send them, for example, on the window glass, then the reflected IR signal will be comaused with the frequency of sounds indoors.

To listen to such a signal to the DA2 output, you must connect an amplitude detector with a low frequency amplifier and replace C10, C11 with capacitors of 100 PF, resistors R21, R22- 300 com, R19, R20 - 3 com.

In general, the capacitance capacitors C10, C11 of the integrator depends on the possibility of obtaining a large level of amplification. The capacity of the capacitors is more, the more smoothed random interference and the more you can get an increase. However, for the sake of this you have to sacrifice the speed of the device.

Methods for protecting speech information from leakage on technical channels

Subsections:

1. Request criteria for the effectiveness of speech information from leakage on technical channels - p.1

2. Specially created technical leakage channels of information - page 7

3. Removing information from glass and combating it (scheme for protection) - page 13

assertion of information from leakage on the acoustic channel is a set of measures that exclude or reducing the possibility of exiting confidential information beyond the controlled zone due to acoustic fields.

5.3.1. General Provisions [A]

The main activities in this form of protection are organizational and organizational and technical measures.

Organizational measures involve the conduct of architectural and planning, spatial and regime measures, and organizationally-equipment - passive (sound insulation, sound absorption) and active (sound position) of events. The implementation and technical measures are not excluded through the use of special protected means of confidential negotiations (Fig. 49).

Architectural and planning measures include the presentation of certain requirements at the design stage of buildings and premises or their reconstruction and adaptation in order to exclude or attenuate the uncontrolled propagation of sound fields directly in airspace or in building structures in the form of 1/10 of structural sound. These requirements may include as a choice of location of premises in Pro -

strequently, and their equipment necessary for acoustic security elements that exclude direct or reflected in the direction of the possible location of the attacker. For these purposes, the doors are equipped with boots there, windows are focused in the direction of protected (controlled) from the presence of unauthorized persons of the territory, etc.

Regime measures provide for strict monitoring of their stay in the controlled area of \u200b\u200bemployees and visitors.

Organizative -Technic measures provide for the use of sound-absorbing agents. Porous and soft wool type materials, dilated carpets, foam concrete, porous dry plaster are good soundproofing and sound-absorbing materials - they have a lot of surfaces of the section between air and a solid, which leads to a multiple reflection and absorption of sound oscillations.

Special hermetic acoustic panels made from high density glass windows and different thicknesses (from 12 to 50 mm) are widely used for lining surfaces of walls and ceilings. Such panels provide absorption of sound and exclude its distribution in wall structures. The degree of sound absorption A, reflection and transmitting sound with obstacles is characterized by sound absorption coefficients, reflections, transmittance T.

The degree of reflection and absorption of sound energy is determined by the frequency of sound and the material of reflecting (absorbing) structures (porosity, configuration, thickness).

It is advisable to arrange soundproofing wall coverings in small areas, since in large rooms, the sound energy is as absorbed as much as possible, without reaching the walls. It is known that the air environment has some sound-absorbing ability and the power of the sound decreases in the air in proportion to the square of the distance from the source.

Inside the room, the volume level sounds higher than in the open space due to repeated reflections from various surfaces that ensure the continuation of the sound even after stopping the sound source (reverb). The reverberation level depends on the degree of sound absorption.

The magnitude of sound absorption A is determined by the coefficient

sound absorption A and the size of the sound absorbing surface:

The values \u200b\u200bof the sound absorption coefficients of various materials are known. For conventional porous materials - felt, wool, porous plaster - it varies within a \u003d 0.2 - 0.8. Brick and concrete almost do not absorb the sound (A \u003d 0.01 -0.03).

The degree of impact of sound when applying sound-absorbing coatings is determined in decibels.

For example, when processing brick walls (a \u003d 0.03) with a porous plaster (A \u003d 0.3), the sound pressure indoors is weakened by 10 dB (8 \u003d 101g £).

5.3.2. Methods and means of protection [A]

Noiseomers are used to determine sound insulation protection efficiency. The noiseomer is a measuring instrument that converts sound pressure fluctuations in the testimony corresponding to the sound pressure level. In the sphere of acoustic protection of speech, analog noiseomers are used (Fig. 50).

According to the accuracy of the testimony, the noiseomers are divided into four classes. Zero-class noisometers serve for laboratory measurements, the first - for field measurements, the second-adultery; Third-grade noiseomers are used for oriented measurements. In practice, the second-class noisomers are used to assess the degree of security of acoustic channels, less often - first.

Measurements of acoustic security are implemented by an exemplary sound source. The exemplary is called a source with a predetermined power level at a certain frequency (frequencies),

It is selected as such a source tape recorder with a signal recorded on the frequencies 500 Hz and 1000 Hz, modulated sinusoidal signal in 100-10 Hz. Having an exemplary sound source and Shu-Momer, you can determine the absorbing rooms of the room, as shown in Fig. 51.

The magnitude of the acoustic pressure of the sample sound source is known. The signal taken from the other side of the wall is measured according to the noiseomer readings. The difference between the indicators and gives the absorption coefficient.

Table 4.

Signal frequency (Hz)

For evaluation measurements of the security of premises from leakage on acoustic and vibration channels, the so-called electronic stethoscopes are used. They allow you to listen to the locomotive negotiations.

through the walls, floors, the heating systems, water supply, ventilation communications and other metal structures. The sensor transforming the mechanical oscillations in the electrical signal is used as a sensitive element. The sensitivity of stethoscopes ranges from 0.3 to 1.5 V / dB. When the sound pressure level is 34 - 60 dB, corresponding to the middle volume of the conversation, modern stethoscopes allow you to listen to the rooms through the walls and other fencing structures with a thickness of up to 1.5 m. After checking with such a stethoscope, possible leakage channels are taken to protect them. As an example, you can bring the electronic stethoscope "Breeze" ("Aleron"). Operating frequency ranges - 300 - 4000 Hz, autonomous power. It is intended to identify the vibration and acoustic channels of the leakage of information circulating in a controlled room, through the fences of the structure or communication, as well as to control the effectiveness of information protection tools.

In cases where passive measures do not provide the necessary security level, active agents are used. Active tools include noise generators - technical devices producing noise-like electronic signals. These signals are fed to the appropriate acoustic or vibration transformation sensors. Acoustic sensors are designed to create acoustic noise in rooms or outside them, and vibrating - for masking noise in enclosing structures. Vibrating sensors are glued to protected structures, creating sound oscillations in them.

As an example of noise generators, you can cite a vibroacoustic loaming system "barrier" ("mask"). The system allows you to protect up to 10 conventional surfaces, has the automatic switching on the VB of ROPRAGERS when the acoustic signal appears. Effective noise band frequency 100 - 6000 Hz (Fig. 53). In fig. 54 An example of accommodation in the protected room of acoustic and vibration-thickers is given.

Figure 54. Option of accommodation sensors

Modern noise generators have an effective frequency band in the range from 100 - 200 Hz to 5000 - 6000 Hz. Separate types of generators have a frequency band up to 10,000 Hz. The number of sensors connected to one generator is different from 1 to 2 to 20 - 30 pieces. This is determined by the appointment and constructive execution of the generator.

The noise generators used in practice allow you to protect information from leakage through walls, ceilings, floors, windows, doors, pipes, ventilation communications and other structures with a fairly high degree of reliability. IN

So, the protection against leakage acoustic channels is implemented:

the use of sound-absorbing cladding, specialized additional doorway tamboors, double window bakes;

the use of acoustic noise of volumes and surfaces;

the closure of ventilation channels, input systems in the premises of heating, power supply, telephone and radio communications;

using special certified premises that exclude the appearance of channel leakage channels.