Patent attributes
A contactless device comprises circuitry storing information, a switch having a first position and a second position, and a fusible link. When the fusible link is intact, wireless reading and writing of the information is enabled regardless of the position of the switch. When the fusible link has been parted, wireless reading of the information is enabled when the switch is in the first position, and wireless reading of the information is disabled when the switch is in the second position. The contactless device may be placed in a non-responsive state, and transformed to a responsive state by parting a second fusible link, or by transmitting an authenticating code to the device. The contactless device may be a card, or some other kind of device.