Chinese have learned to bug rooms with fiber-optic cables

Chinese have learned to bug rooms with fiber-optic cables

Researchers from Qinghua University in China have developed inter-house chatter techniques for fibre-optic cables, which are used, for example, to provide an Internet connection so that they can be found everywhere. The results of scientists' work have recently been published on the Internet.

The fact is that sound fluctuations cause variations in air pressure that cause microvibrates in fibre-optic cables that are modularized with cable-transmitted light waves. The resulting distortions can be analysed for sufficiently large removal by using the Maha-Tender laser interferometer.

In the course of the research, scientists were able to fully recognize the speech when a three-metre open section of fibre-optic cable was available in the room. The distortion analysis was carried out at a distance of 1.1 km from the room being monitored. It is noted that the audition range and ability to filter interference correlates with the length of the fibre-optic cable in the room.

As a result, scientists have established that the definition and restoration of the signal in the optical networks can be implemented covertly for the audition object and without disrupting the communication functions used. For the hidden connection to the communication channel, researchers have used a multilexor with a wave split . The lowering of the background noise level can be achieved by further balancing the interferometer ' s shoulders.

In order to counter this audition method, it is recommended to reduce the length of optical cables in the room and place them in rigid cables. It is also possible to reduce the audition efficiency by using tilting cables. ) Cable manufacturers are encouraged to use high-vulnerability materials such as metal and glass to cover the fibre.