To calm consumer fears about having card account numbers stolen wirelessly, University of Pittsburgh has developed a way to switch contactless cards off automatically when they are not in use.

The university's Swanson School of Engineering said last week that it is applying for a patent on a process that uses a person's hand as a "switch" to complete the circuit that activates the card's antenna. When a user touches the card in a particular spot, the switch comes on and the card can transmit payment data. When the card is not being held, the circuit is broken.

This approach "is simple and very inexpensive to integrate," Marlin Mickle, a professor and the executive director of the school's RFID Center for Excellence, said in a press release Feb. 16.

Contactless cards already use several security measures to thwart potential card thieves from grabbing useful account data over the air. For example, a contactless card transaction requires a one-time-use code the card provides each time it is tapped against a reader. If that code is stolen, it cannot be reused.

Contact transactions, whether made with a magnetic stripe or a secure EMV chip, use different codes.