Date Added: Aug 2012
In this paper, the authors consider a good authentication system using 2D Bar-Codes (2D-BC) from the point of view of the opponent. An estimator that one can use to product a fake was proposed and its performance was derived through theoretical results and simulations on real printed and scanned 2D-BCs. While both the model and the tests conducted on real data agree on the general conclusion that Eve's estimation performance increases when collecting 2D-BCs, the slope of the curves, however, differs greatly. It is shown that the opponent can produce a fake that successfully fools the detector with a reasonable number of genuine goods.