Two PIN numbers are better than one when it comes to safeguarding smart cards, say Japanese inventors Hideki Hashimoto and Hirokazu Fukatsu. Their idea is to key in one number in the usual way while the other is stored in a tiny electronic tag (US 2003/0159040).
The tag is attached to another personal item, such as spectacles or a cellphone. It broadcasts the number to a reader when the smart card is used, and the transaction only goes ahead if the two match. If the card and PIN are stolen they are useless – unless the thief knows which…
