The use of cards has now reached such a level throughout the Nordic region that a serious disruption to a large parts of the system would have serious consequences, said Lars Nyberg, a deputy governor of the Riksbank.

Nyberg said the increasing use of cards placed increasingly high demands on safety and on the reliability of the technical infrastructure that supports the cards. He said banknotes retained their value as a means of payment even if the technical infrastructure is off-line, while