Experimental scrambling and noise reduction applied to the optical encryption of QR codes

JOHN FREDY BARRERA; ALEJANDRO VELEZ; ROBERTO TORROBA

OPTICS EXPRESS

OPTICAL SOC AMER

Lugar: Washington; Año: 2014 vol. 22 p. 20268 - 20277

1094-4087

In this contribution, we implement two techniques to reinforce optical encryption, which we restrict in particular to the QR codes, but could be applied in a general encoding situation. To our knowledge, we present the first experimental-positional optical scrambling merged with an optical encryption procedure. The inclusion of an experimental scrambling technique in an optical encryption protocol, in particular dealing with a QR code container, adds more protection to the encoding proposal. Additionally, a nonlinear normalization technique is applied to reduce the noise over the recovered images besides increasing the security against attacks. The opto-digital techniques employ an interferometric arrangement and a joint transform correlator encrypting architecture. The experimental results demonstrate the capability of the methods to accomplish the task.