A chaos-based approach to secure - Communications

Ensuring the security of information transmitted over the Internet is an urgent priority in the increasingly digital world. A unique approach to safeguarding data transmission by embedding messages with optical chaos is described, that is known as Optical Chaotic Cryptography. The approach makes use of a pair of lasers that generate chaos, a behavior of a large class of nonlinear systems. A standard DFB telecommunication laser routed to chaos exhibits a widened spectrum, typically on the order of 10-100 GHz, showing a non-periodic and complex behavior. The transmitter produces an optical carrier with an extremely broadened spectrum. Synchronization is usually obtained by injecting a part of chaotic output of the transmitting laser into the receiver laser, to extract the hidden signal. One notable characteristic of the chaotic regime is its strong sensitivity to starting conditions and systems parameters.