Nowadays, industrial and state espionage is booming. Thanks to the development of information technology, new methods of tracking and illegally obtaining information about the activities of their competitors appear daily. Technical channels for confidential information leakage arise from physical transformers. Absolutely any electronic device in the room can become a source of leakage, in turn, it can be detected and neutralized. Moreover, neutralizing it is often easier than finding it.
General information
Information can be transmitted through a field or substance. You can steal a sound wave, intercept electromagnetic radiation or use the old methods and pick up paper, there are a lot of options. But all of them are only carriers. A leak in itself is an uncontrolled exit of hidden information outside 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 him 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
The classification of technical channels of information leakage is based on their division into subgroups. There are natural and specially created channels. The former may appear due to incidental electromagnetic radiation during information processing or with extraneous conductors. In the second case, devices aimed at interception are specially introduced into the system. For this, receiving devices and broadband directional antennas are used. When considering the technical channels of information leakage, it is also worth considering the sources of interference.
Acoustic Espionage Protection
The microphone effect can occur in any device where there are inductors, piezoelectric transducers or variable capacitors. 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 turning off or changing the device. The second is the connection of special protective devices to telephone lines.
Modern devices are made in the form of telephone outlets, so competitors will not be able to visually determine their presence. Before securing the technical channel of information leakage, you should check whether it really has a microphone effect. For this, special equipment is used that detects interference, noise and so on.
Protection against electromagnetic spying
Telecommunication facilities and other 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. It is through them that a leak of information can occur. The nature of this radiation directly depends on the range of the equipment.
When collecting information from short-range devices, use the magnetic component, long-range - electromagnetic radiation. Thus, the technical channel of information leakage will create an interference field. It will depend on the size of the premises, the locations of the reading equipment and the materials from which it is created. To determine the leak, you need to check both the near and far fields.
Basic protection methods
At the moment, modern technology allows you to determine the voltage of the electromagnetic field very accurately. For this, special tools and analytics are used. But to determine how intense the total field is, for now, is precisely impossible. It is best to rationally place the devices in the room so as not to create an overlap of their radiation on each other. This will greatly simplify the verification and identification of technical channels for information leakage.
The most important thing in protecting against such leaks is to limit the signals, that is, they should not go beyond the company. There are norms and permissible values of the waves that must be installed on the equipment in order to prevent the possibility of gaining access to the communication lines of competitors. In order to protect data from spurious emissions, a number of measures should be taken, namely:
- Install all devices potentially leading to leakage in places as far as possible from the border of the territory that is being protected.
- Provide shielding of premises, buildings and communications in the company.
- It is best to use local systems that do not go beyond the boundaries of the territory.
- All interchanges in the power supply and grounding networks should be done exclusively in a protected area.
- You can also install suppression filters.
If there is a suspicion that protecting information from leakage through technical channels does not help anymore and there is a leak, then selective voltmeters, measuring receivers, sector analyzers and other specific equipment can be used to detect it.
Power Spy Protection
Leakage from the controlled area can also occur through the power grid to which technical equipment is connected. Most often, power supplies emitting high frequencies are used in such a way for such connections and information theft. In order to carry out protective measures, circuit layout methods are mainly used.
To do this, install specialized surge protectors, converters and similar equipment that protects the room from unnecessary surges in the waves in electric networks. 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 occurs.
Grounding
It is also important to pay attention to grounding. It is very important to properly install all the equipment and protect it from intruders. Outdoor grounding is carried out at a depth of more than one and a half meters. In the building, they need to be installed in such a way that you can regularly check for integrity and the presence of additional connections.
Mutual influences in communication lines
It is known that information transmission lines can affect each other. The influencing circuit is the chain that creates the primary effect on the electromagnetic field. Next are the chains that this field acts on. In addition to the direct influence of the circuits on each other, there is also an indirect effect, which can arise due to the reflection of signals. Exposure can be systematic and random.
Basically, they arise due to wires of the same size located in the aboveground space. Random influences appear due to a combination of circumstances that cannot be estimated or predicted. To create exposure conditions, one cable must be shielded, the other not. From this it follows that technical interference is not safe, and through them technical exploration of information leakage channels can be carried out. If the cables are damaged or corroded, which very often happens in practice, they begin to emit strong signals in the electromagnetic field.
Exposure protection
Equipment can be protected from mutual interference. For this, the necessary measures should be applied, namely:
- Use transmission systems and communication lines in which the mutual impact indicators are minimal. You can almost completely solve the problem if you install only fiber-optic lines and coaxial cables.
- It is rational to choose cables for various systems, that is, try to compensate for all interference between symmetrical lines.
- Carry out screening of the circuits with flexible and rigid screens, this will reduce 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 fiber-optic communications that become technical channels for the leakage of acoustic information. There are a number of reasons why these channels can cause the loss and transfer of confidential, important information to attackers:
- The joined fibers are radially inconsistent.
- The axes of the optical fibers are inconsistent in angular type.
- A gap was formed between the ends of the optical fibers.
- The surfaces of the ends of the fibers are mutually non-parallel.
- There was a difference in the diameter of the cores of the fibers that are joined together.
The above reasons can become a source of radiation of light signals into the electromagnetic field in a room. Because of this, an acousto-optical effect may occur. Acoustic pressure will appear on the waveguide, due to which its value can change. To protect the technical channels of speech information leakage, 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 optical fibers 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 before installing it with special substances with high bulk elastic moduli. Most often, aluminum, nickel or glass is used for this.
Conclusion
At the moment, there are various means of information leakage through technical channels. Given the development of information technology and the increased number of opportunities for industrial espionage, any company that has confidential information should protect itself from such leaks. If you approach the issue correctly and use all kinds of protective methods, 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 frequency it is worth checking all means of communication and possible technical channels in order to detect and neutralize devices that read and transmit information.
Nowadays, it is completely impossible to predict how attackers will get into the guarded room and install special reading equipment. But constant monitoring and protective equipment can protect against this. In addition, the advent of shielded and reflective antennas has significantly increased the ability to steal information. Therefore, it is very important to monitor the electromagnetic field in and around the room. Any means of technical espionage can be detected and neutralized, most importantly, deal with this issue and use available technical devices designed for this.