Technical channel of information leakage. Identification of technical channels of information leakage

In our time, industrial and state espionage is flourishing. Thanks to the development of information technology, new methods of monitoring and unlawfully obtaining information about the activities of their competitors appear daily. Technical channels for leakage of confidential information arise because of physical converters. Quite any electronic device in the room can become a source of leakage, in turn, it can be detected and rendered harmless. And to neutralize it is often easier than to find.

General information

You can send information through a field or substance. You can steal a sound wave, intercept electromagnetic radiation or use old methods and pick up paper, there are a lot of options. But they are all carriers only. The leak itself is an uncontrolled way out of the hidden information beyond the boundaries of the enterprise or the circle of people who possessed it.

But the term "technical channel of information leakage" means the physical path from the source to the attacker. It is through it that access to hidden data is opened. At the moment, there are four types of information transfer, namely sound and electromagnetic waves, light rays and materials.

Classification

Classification of technical channels of information leakage is based on dividing them into subgroups. There are natural and specially created channels. The first may appear due to spurious electromagnetic emissions during the processing of information or with extraneous conductors. In the second case, devices aimed at interception are specially introduced into the system. For this, receivers and broadband directional antennas are used. Considering the technical channels of information leakage, it is also necessary to take into account sources of interference.

Protection against acoustic espionage

The microphone effect can occur in any device where there are coils of inductance, piezo-optical converters or capacitors of variable capacity. Any conversation causes fluctuations in the field, which these devices can catch. To protect the organization from this kind of leakage, organizational and technical measures are used. The first is switching off or changing the device. Second - the connection of special protective devices to telephone lines.

Modern devices are made in the form of telephone sockets, so that they can not be determined visually by competitors. Before securing the technical channel of information leakage, it should be checked whether it really has a microphone effect. For this purpose, special equipment is used that detects interference, noise and so on.

Protection against electromagnetic espionage

Telecommunication facilities and other radio electronic devices have electromagnetic radiation. It is necessary to transmit data, but there are also unwanted waves in the form of out-of-band, electromagnetic and noise waves. It is through them that there may be a leak of information. The nature of this radiation is directly dependent on the range of the equipment.

When collecting information from short-range devices, the magnetic component is used, and the far-field component is electromagnetic radiation. Thus, the technical information leakage channel will create a jamming field. It will depend on the size of the premises, the locations of the reading equipment and the materials from which it was created. To determine the leak, you need to check both fields, both near and far.

Basic methods of protection

At the moment, modern technology allows you to determine the voltage of the electromagnetic field very accurately. Special tools and analytics are used for this. But to determine how much the total field is strained, for the time being it is precisely impossible. It is best to place the instruments indoors in order not to create a superposition of their radiation on each other. This will greatly simplify the verification and identification of technical channels of information leakage.

The most important in protecting against such leaks is the restriction of signals, that is, they should not go beyond the limits of the company. There are norms and permissible values of waves that need to be installed on equipment to prevent access to competitor communication lines. To protect data from spurious emissions, a number of activities should be carried out, namely:

• Install all devices potentially leading to a leak in areas as far from the border as possible, which is protected.
• Provide for shielding of premises, buildings and communications in the firm.
• It is best to use local systems that do not have a way out of the territory.
• All interchanges in the supply network and grounding do exclusively in the protected area.
• You can also set suppressive filters.

If there is a suspicion that the protection of information from leakage through technical channels does not help and there is a leak, selective voltmeters, measuring receivers, sector analyzers and other specific equipment can be used to detect it.

Protection against espionage through power circuits

Leakage from the controlled area can also occur through the electrical network to which the technical means are connected. Most often for such connections and the theft of information in a similar manner, power supplies that emit high frequencies are used. In order to carry out protective measures, the methods of circuit distribution are mainly used.

To do this, install specialized network filters, converters and similar equipment that protects the room from unnecessary surges in the power grid. With a more serious approach, separate transformers are installed in the protected and protected area through which electricity is transferred to the building. In this way, the most reliable protection of information from leakage through technical channels through the power grid.

Earthing

It is also important to pay attention to grounding. It is very important to properly install all equipment and protect it from intruders. Installation of grounding outdoors is carried out at a depth of more than one and a half meters. In the building, they must be installed in such a way that you can regularly check for integrity and availability of additional connections.

Mutual influences in communication lines

It is known that information transmission lines can influence one another. An influential chain is the chain that creates a primary influence on the electromagnetic field. Further, there are already circuits on which this field acts. In addition to the direct influence of the chains on each other, there is also an indirect effect that can arise from the reflection of signals. The impact can be systematic and random.

Basically, they arise because of wires of the same size, located in the above-ground space. Random influences appear due to a combination of circumstances that can not be estimated or anticipated. To create exposure conditions, one cable must be shielded, the other cable not. It follows that technical guidance is not safe, and technical reconnaissance of information leakage channels can be carried out through them. If the cables are damaged or corroded, which often happens in practice, they begin to radiate strong signals into the electromagnetic field.

Protection from exposure

The equipment can be protected from mutual influence. For this, the necessary measures should be applied, namely:

• Use transmission systems and communication lines, in which the indicators of mutual influence are minimal. You can almost completely solve the problem if you install only fiber-optic lines and coaxial cables.
• Choosing cables for different systems is rational, that is, try to compensate for all the lines between the symmetrical lines.
• To carry out shielding of circuits by flexible and rigid screens, this will ensure a reduction in mutual interaction due to the weakening of the intensity of the electromagnetic field through the screen.

Protection against espionage in fiber-optic lines and communication systems

It is the fiber-optic connections that become the technical channels for the leakage of acoustic information. There are a number of reasons why these channels can cause the loss and transmission of confidential, sensitive information to intruders:

• The fibers to be joined are radially inconsistent.
• The optical fiber axes are inconsistent in the angular type.
• A gap has formed between the ends of the light guides.
• The surfaces of the ends of the fibers have a mutual non-parallelism.
• There was a difference in the diameter of the cores of the fibers, which are joined together.

The above reasons can become a source of radiation of light signals in the electromagnetic field in the room. Because of this, an acousto-optical effect can occur. Acoustic pressure will arise on the waveguide, because of which its magnitude may change. In order to protect the technical channels for the leakage of speech information, it is first necessary to determine why light arises and spreads at the physical level. Then you need to secure the waveguide, eliminating any acoustic impact on it.

It should be borne in mind that the optical fiber covering the cable can affect the sensitivity of the light guides, depending on the material of which it is made, and the thickness of the wire. To ensure a decrease in sensitivity, it is possible to coat the fiber prior to its installation with special substances that have high values of bulk moduli of elasticity. Most often for this use aluminum, nickel or glass.

Conclusion

At the moment, there are various means of leaking information through technical channels. Taking into account the development of information technologies and the increased number of opportunities for industrial espionage, any enterprise that possesses confidential information must protect itself from such leakages. If you correctly approach the issue and use all sorts of protective techniques, you can significantly reduce the risk of leakage of important information for the company. If all these techniques have not been carried out, then with a certain periodicity it is worth checking all communication means and possible technical channels in order to detect and neutralize devices that read and transmit information.

In our time, it is impossible to foresee how the attackers will enter the protected premises and install special equipment for reading. But constant monitoring and protective measures can protect against this. In addition, the appearance of shielded and reflective antennas has significantly increased the possibilities of information theft. Therefore, it is very important to monitor the electromagnetic field in and around the room. Any means of technical espionage can be detected and rendered harmless, the main thing is to deal with this issue and use the available technical devices designed for this.