Checking papers does no good if the papers are forged

From Bruce Schneier’s “News” (Crypto-Gram Newsletter: 15 April 2006):

Undercover investigators were able to smuggle radioactive materials into the U.S. It set off alarms at border checkpoints, but the smugglers had forged import licenses from the Nuclear Regulatory Commission, based on an image of the real document they found on the Internet. Unfortunately, the border agents had no way to confirm the validity of import licenses. I’ve written about this problem before, and it’s one I think will get worse in the future. Verification systems are often the weakest link of authentication. Improving authentication tokens won’t improve security unless the verification systems improve as well.