One idea that has taken root is the use of a token the size of a key fob that generates a random six-digit password every 60 seconds.

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Each one is stuffed with several hundred tiny glass spheres or shards, of random size and glued in place in a random pattern so that each token, which can be inserted in a credit card, is unique.

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The cryptographic token, in development for a year at MIT's Center for Bits and Atoms, is the size of a postage stamp and as thick as a credit card.

FORBES: Magazine Article