All that the user needs to do is swipe the card at the existing check-out machine and enter a four digit PIN.

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Far more common--but still damaging--are the high-volume crime spikes, spam e-mail distribution and "phishing, " a pernicious technique for stealing credit-card information. (For more on online scams, check out "Where The Scammers Are".) The carnage is hard to pin down in dollar terms, but Marcus Ranum, chief security officer of Tenable Security, says it's "billions upon billions"--far more than all "major" hacking incidents combined.

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The time it takes to check your hand remains a little longer than it would take you to drum in your typical four-digit PIN, but in our brief test, it was able to discriminate between two Engadget editors' hands.

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