CMOS 2.4μm chaotic oscillator: Experimental verification of chaotic encryption of audio

The Letter reports the first experimental verification of chaotic encryption of audio using custom monolithic chaotic oscillators. We use Gm-C techniques to realise a chaotic modulator/ demodulator IC that implements a 3rd-order nonlinear differential equation. This has been fabricated in 2.4μm double-poly technology and includes on-chip tuning circuitry based on amplitude detection. Measurements demonstrate how to exploit the synchronisation between two of these ICs for encrypted transmission