Mode Division Multiplexing as a Technique Counteracting Intrusion to Multimode Fiber Systems

The presented material shows that a fruitful way to counteract illegal data reading from the system trunk fiber could be application of mode division multiplexing technique, particularly under special manner of data transmission via the few- or multimode trunk fiber. The principle of namely data distributive technique is described. The content of the technique include division of the data sequence to time periods each containing several data blocks and simultaneous transmission of these blocks over different modes of the trunk fiber. If eavesdropping occurs, the illegally registered signal is a mix of different data blocks. Transmission of random signals via the extra fiber mode could provide additional impeding of decoding the illegally read data. At the end of the line, reversal processing of the received data restores the original data sequence. Advantageous feature of the technique is full compatibility with all developed methods of data security. Cooperative application of these techniques could enhance the protection of transmitted data.