Synchronization of chaotic circuits through real channels

Chaotic encryption is currently a popular topic in technical journals. A number of articles have been written proposing novel methods of encrypting data using chaotic signals. Most of the encryption schemes rely on the ability of chaotic systems to be synchronized. Pecora and Carroll, the noted experts on this topic, have published a number of papers describing the theory and presenting simulations of synchronized circuits. Their papers are most often cited as the source of synchronization theory. However, no tests have been performed exploring synchronization across anything but ideal channels.

This paper presents a brief background of chaotic signals. The basic theory of synchronizing chaotic signals is covered next. Finally a series of experiments are performed testing the ability of a chaotic signal to synchronize over various audio grade channels, the most often used medium for encrypted information.

The experiments show that there are considerable problems getting chaotic circuits to synchronize over non-ideal channels. The failure to synchronize is discussed with respect to each channel tested. A number of additional research opportunities are presented.