Spatial Data Encryption Using Phase Conjugating Lenses

• Published in: IEEE transactions on antennas and propagation 2012-06, Vol.60 (6), p.2913-2920
• Main Authors: Malyuskin, O., Fusco, V.
• Format: Article
• Language: English
• Subjects: Antenna array; Antennas; Applied classical electromagnetism; Applied sciences; Arrays; Binary phase shift keying; Bit error rate; bit error rate analysis; communication system security; Demodulation; Electromagnetic wave propagation, radiowave propagation; Electromagnetism; electron and ion optics; Encryption; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Lenses; Modulation; phase conjugation; phase detection; phase shift keying; Physics; Polycarbonates; Pumps; Radiocommunications; Secret; Signal detection; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments)
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2012.2194661

Spatial encryption of a BPSK modulated signal radiated by a dipole-like antenna and transmitted through a phase conjugating lens (PCL) or through a system of PC lenses in free space is theoretically studied using a time domain electromagnetic (EM) formulation. The PC lenses are composed of antenna elements interconnected via phase conjugating circuitry. It is shown that when the PCLs are modulated with a phase encoded pump sequence at the same rate as the BPSK information signal, spatial encryption in the space between the two PCLs is possible, while the signal can only be decoded in well defined spatial regions after passing a second PCL. The effect that phase offset between PCL modulation signals has on viable spatial demodulation regions is also discussed. We show also that the signal detection area can be further confined using a third phase encoded pumped PCL located behind the second lens and modulated by an arbitrary BPSK pump sequence. The considered spatial encryption mechanism can find applications in secure communications.