Systems and methods for protecting privacy in transmitting an analog
information signal. The present invention combines the information signal
with an analog random signal generated by a chaotic circuit and transmits
the signal. The received signal is synchronized using a receiving chaotic
circuit. The received signal is demodulated using a synchronized replica
of the analog random signal. The information signal is recovered since
the product of the random signals generated in the transmitter and in the
receiver, is unity. Techniques used in the present invention for
generating chaos, synchronization, and signal recovery are also
disclosed.