25 research outputs found
Private Communications Using Optical Chaos
After a brief summary of the basic methods for secure transmission using optical chaos, we report on most recent achievements, namely, on the comparison between the standard two-laser and the three-laser schemes and on the network architecture for multiuser secure transmission. From our investigations, we found that while both the basic two-laser and the three-laser schemes are suitable to secure data exchange, the three-laser scheme offers a better level of privacy due to its symmetrical topology. Moreover, while transmission based on optical chaos is usually restricted to point-to-point interconnections, a more advanced solution, derived from the well-known public key cryptography, allows for private message transmission between any couple of subscribers in a network
Assessing security of chaos communications against eavesdropping by pump detection
In this paper, we numerically evaluate a method which could be tried by an eavesdropper to force the standard two-laser scheme of chaos private transmission. This method is based on detection of the voltage arising across a semiconductor laser junction, and uses two lasers: one is synchronized to the transmitter (thus, reproducing chaos and rejecting the message), the other is selected and trimmed to copy the transmitter (i.e., reproducing both chaos and the message). The message is then obtained by difference and chaos cancellation. By assuming the usual parameter mismatch, which is expected to be achieved by an eavesdropper, it is shown that the method does not represent a substantial threat to the privacy of the transmission system. The scheme is also briefly considered as an alternative, but less performant, scheme for chaotic cryptography. Simulations are based on the Lang-Kobayashi model
Enhancing Privacy of Chaotic Communications by Double Masking
In this paper, we numerically demonstrate that the
performances of private transmission using chaotic lasers can be
substantially improved by double masking the message by a suitable
scheme. In addition to standard optical chaos, our method
makes use of the chaotic voltage waveform available across the
transmitter laser junction.With respect to the standard setup, the
new one requires only one more electrical amplifier and a passive
adder at the transmitter, while the receiver remains unchanged.
It has been found that with this new scheme, synchronization
quality is significantly improved for the twin lasers, while this
is not the case for an unmatched laser pair. This results in an
increased bit error rate differential between the authorized user
and an eavesdropper, thus enhancing privacy. Simulations have
been performed with the Lang–Kobayashi model