Title :
A Modulator/Demodulator CMOS IC for Chaotic Encryption of Audio
Author :
Delgado-Restituto, M. ; Rodríguez-Vázquez, A. ; Liñán, M.
Author_Institution :
Dept. of Analog Design, CNM, Edificio CICA, C/ Tarfia sn, 41012-Sevilla, SPAIN. Phone # 34 5 4623811, FAX # 34 5 4624506
Abstract :
This paper reports the first experimental verification of chaotic encryption of audio signals using integrated circuits. It is based on a gm-C modulator/demodulator analog CMOS IC that implements a 3rd-order nonlinear differential equation. This has been fabricated in 2.4¿m double-poly technology and includes on-chip tuning circuitry based on amplitude detection. It is capable of generating controllable continuous-time chaotic signals. Also, measurements demonstrate how to exploit the synchronization between two of them for encrypted transmission. In these experiments, the worst-case signal to noise ratio of the recovered signal is greater than +40dB (at the low corner of the audio spectrum) with less than ¿0.2dB loss of the input signal power. At higher frequencies, the signal-to-noise ratio rises up to +60dB, while retaining similar losses at the receiver.
Keywords :
Analog integrated circuits; CMOS analog integrated circuits; CMOS integrated circuits; CMOS technology; Chaos; Cryptography; Demodulation; Differential equations; Integrated circuit technology; Signal to noise ratio;
Conference_Titel :
Solid-State Circuits Conference, 1995. ESSCIRC '95. Twenty-first European
Conference_Location :
Lille, France
Print_ISBN :
2-86332-180-3
