KenBIT company, working together with the Military University of Technology, has developed a special purpose Securelight-1LR detection system. It has been designed to detect any case in which the continuity of connection could be interrupted in case of fibre-optic connection, e.g. because of an attempt to plant a bug within the wire, or because of an unauthorized connection made to the data-transmission tract.
Optical Fiber Connection Does Not Ensure Data Transfer Security on Its Own
Fiber-optic communication is commonly considered to be the safest of the data transfer mediums available. Theoretically, besides “input” and “output”, no possibility to access the data stream exists. Such communication lines do not generate any magnetic or electrical fields. Signatures as such would make it plausible to measure the internal data transfer externally.
Considering the newly emerging “bugging” options, the fibre optic communication has ceased to be an independent measure that would ensure security of data transfer. Steps had to be made to treat it as a normal medium that would require additional encryption of the transferred data. Furthermore, a high demand emerged with regards to systems that would inform the user about potential damage or mechanical changes emerging with regards to fibre optics. This would also apply to any attempts that could be made to access the transferred data.
In reality there are some options to “bug” the fibre optics, even though this poses quite a significant challenge. For example, the research suggests that 1% of the laser signal may leak out of an optical fibre at an angle of 180 degrees. The light leaking through the external wall of the optical fibre may also be made available by removing the acrylic layer. Such breaches are difficult to be detected by any system, as signal loss is very low in such case. Special bend coupler detector systems are also being manufactured. Their purpose is to receive the laser signal that penetrates the bent fibre optical wire. The said detectors are available on the generally accessible market, even in e-commerce, at prices around several hundred dollars.
As it turns out, any signal attenuation changes created by a bended wire for instance, can be easily detected. The phenomenon in question is also used in case of so called detection fibre optics (fibre optic sensors) that are buried in the ground, and when stepped over or driven over, signal it to the user that a vehicle or human being passed by. Such signal interruptions that are possible to be detected in proper data transmission lines may be even caused by acoustic vibrations generated by the cars passing by.
In case of the data transmission tracts, the designers take every step that would make it impossible for the signal to be influenced by the external factors. Moreover, steps are being made to make it more difficult to intercept the data by anyone but intended recipient and by the sender.
Polish Fibre Optics Security Solutions
KenBIT company, working together with the Optronics Institute of the Military University of Technology, has developed the Securelight-1LR fiber optics interference sensor. Its purpose is to detect and locate any mechanical and physical interference within the optical fibre data transfer systems. The sensor has been created as a result of the “System for monitoring of fibre optical connection integrity for the purpose of protecting it from unauthorized accessing of confidential data” research and development initiative. The said work underwent implementation from 18th December 2012 until 19th December 2015. The aforesaid sensor uses interference contrast analysis and signal processing in order to generate alerts and locate the place where the internal interference occurs.
The designers also took the external interference measurements being influenced into account, by creating a compensation system that would act against the sine background signals through proper modulation of the power supply. The system would automatically adapt to the environmental changes having an impact on the sensitive portion of the data transfer. A single measurement system is capable of monitoring zones within a radius of up to 49 km. It also allows the user to point out the location of potential interference at accuracy defined as 0.05% of the total length of the optical fiber. This makes it possible to subdivide the secure zone into monitored areas within radius of several kilometers, also allowing the user to freely configure the layout of the zones. The Securelight-1LR sensor-based system may be thus coupled with maps, allowing for visualization of locations where the alerts take place.
The sensor itself is based on two Mach–Zehnder interferometers, utilizing the very same optical fibers, but arranged in the opposite direction with regards to propagation of light. The whole system is operated within five basic stages:
Computation of mutual correlation and subsequent normalization;
Determining the interference location on the basis of correlation;
Verifying whether the location finds itself in the designated area;
Verifying whether the level of correlation exceeds the value set;
Verifying the shape of correlation at the place of interference.
The designers also took care of high security of the data transmitted through the supervised channel. Furthermore, the whole protection suite is easy to set up. Any damage emerging due to the damage of the transmission tract remains easy to be rectified, thanks to the option of using the standard telecommunications-grade fiber optics. This also provides the user with an ability of rapidly recovering the operation of the data transmission system.