The reader pulls up a ten-digit signaturecode, created for that particular sale or cash withdrawal, and debits or loads the card with the appropriate amount of money.
Daniel Rostenkowski, the Democratic head of the House Ways and Means committee, wanted to close loopholes in the interest of a cleaner tax code and was looking for a signature achievement to boot.
It is signature based which means it relies on a massive collection of snippets of text and code that researchers have discovered over the years are associated with unwanted network traffic, be it worms, port scans, or intrusions.