Years ago, I could read "instant win" lottery cards and still leave them as new by using the laser photoacoustic effect. A low-power chopped laser beam is focused and line-scans the target while a microphone picks up the acoustic waves caused by differential absorption of the laser light as it sweeps the line. By phase-shifting the received acoustic signal versus the chopped light signal (they have the same frequency), you can read at different depths of the target. Adjusting to hearing at the depth of the paper substrate, below the covering ink, all markings could be read as if the covering ink did not exist, line by line.
The apparatus could be built today by something like $500, I believe, using parts readily available. Distributors of the "instant lottery" cards could, without detection, separate the winning cards. Unlike ATM cards, there are no cards that must be stolen at the same time for the attack to be successful. Cheers, Ed Gerck Perry E. Metzger wrote:
Often, banks send people PINs for their accounts by printing them on tamper "secure" mailers. Some folks at Cambridge have discovered that it is easy to read the PINs without opening the seals... http://news.bbc.co.uk/1/hi/technology/4183330.stm
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