Human and/or Digital Interrogation of Tax Stamps

An intriguing and important discussion regarding the relative role of human senses and digital methods in authentication has been sparked by two contrasting presentations at the recent Tax Stamp Forum™. Ian Lancaster, who presented one of those papers, here describes the contrasting presentations and the follow-up discussion.

A fingerprinting technique

On the first morning of the forum Avi Chaudhuri, Chief Scientist at Systech, gave a paper titled The Perfect Tax Stamp, in which he argued for the use of ‘fingerprint’ methods to authenticate stamps – specifically Systech’s new e-Fingerprint^® technique. This works on the basis that if a tax stamp carries a two-dimensional barcode (eg. a QR or datamatrix code), the barcode pattern printed on each stamp will unavoidably vary (caused by environmental variations, dust, line speed, vibrations and printing or substrate imperfections).

The e-Fingerprint solution involves the use of a high-resolution camera to capture the printed code and these stochastic variations. They are then algorithmically digitised for storing on a database (data repository in Dr Chaudhuri’s words) which holds the file of every recorded barcode. The examiner then captures the barcode on each stamp using the UniSecure proprietary app on his or her smartphone; the app connects to the database to compare this with the genuine code and report to the examiner whether the code (and therefore the stamp it’s printed on) is genuine or not.