Digital polarization-sensitive speckle correlation as security validation technique

Abstract

We implement a validation technique, based on polarization encoding using the classical digital speckle pattern correlation. A validation mark is generated, which can be magnetically affixed or by means of a chip attached to a primary document. Besides, a decoding key is also generated in the same setup to be sent to the client. In our method, security is twofold by the speckle and polarization characteristics of the procedure. Both encoding and decoding keys are stored digitally. The validation can be achieved by a subtraction operation between both keys performed with conventional software. No additional experimental setups are required in the decoding step. Experimental results are presented to illustrate the method.