Cryptography in GSM networks.
Cryptography in GSM networks.
There are not many practical options for such devices.
An example of a scrambler is the Swiss company Crypto AG's HC-2413. As far as can be judged from the photograph, it is based on the Sagem MC-850 phone, with a scrambling device added to the bottom.
HC-2413
HC-2413 provides a full-duplex secure connection not only with similar devices, but also with fixed telephone terminals HC-2203 of the same company. For encryption, the device uses a 128-bit key and its own algorithm developed by Crypto AG.
Using such a device allows you to protect your conversations from eavesdropping at any point in the transmission (of course, except for direct eavesdropping by ultra-sensitive microphones located in close proximity to the subscriber).
Another device that provides complete traffic protection is the TopSec GSM device, created on the basis of the Siemens S35 phone by the German company Rohde & Swartz.
TopSec GSM
The device is a regular Siemens S35 phone, upgraded with a special crypto chip. Encryption is enabled by a special option in the phone menu. In secure mode, the phone can work with both a second TopSec phone and an ISDN phone ELCRODAT 6-2 from the same company.
Security is provided by traffic encryption with a 128-bit key, and the session key is calculated using a 1024-bit key, which provides additional protection. A distinctive feature of this phone is that encrypted packets are created in it in such a way that they are transparently perceived and transmitted over GSM networks, like regular GSM packets.
There is information about the price of such a phone: $2700. Such a high price, however, did not prevent the high popularity of TopSec GSM. Thus, the Bundeswehr (German armed forces) last year signed a contract for the supply of such phones for their own needs.
In April 2000, the Swedish company Sectra Communications began production of an export model of its Tiger mobile digital phone.
Tiger
Sectra Tiger models, using encryption technology with keys from 56 to 256 bits long, provide secure communication over public GSM networks.
Sectra offers both centralized and distributed key management systems, either using the company's own SmartKey smart cards or the KeyBeam infrared communication feature of Tiger models. Keys can be generated on the phone itself and sent directly to a select group of users. In the future, Sectra intends to develop versions of its phones for other wireless standards, in particular the CDMA standard, which is widely used in the United States.
Strict government regulation of the import and export of encryption technologies, according to company representatives, significantly limits the sales of such mobile phones. In addition to government permission, buyers also need a lot of money. «Civilian» versions of Tiger mobile phones will cost about $ 5,000, a discount is provided only to those buyers who purchase a batch of several hundred devices.
The device has the dimensions of a modern cell phone and weighs 197 g, but it differs from traditional devices in its unusual antenna location, which is installed at the bottom, not at the top. The mobile phone also has a slot for installing smart cards from which the encryption key is read.
A few words about the situation in Russia. Since the devices described above are not certified by FAPSI and other registration organizations, their use in our country is, unfortunately, prohibited. Of course, if you bring a couple of such phones, most likely no one will notice their use. Only if he doesn't specifically look for it, which seems unlikely, since otherwise there would be no point in defending himself. But if he does find it, then measures may well be taken.