i dont think it is super secret stuff. I was thinking about the luhn algorithm since i read the article today, but the real story is (could be) that the guy is

i dont think it is super secret stuff. I was thinking about the luhn algorithm since i read the article today, but the real story is (could be) that the guy is just a newspaper vendor and he do that by hand. If that is true.., well, chapeau.., bad thing is that the guy was stealing, but is impresive if he never read about the algorithm. the other funny part is his last name...