| 摘要 |
<p>A passive device shield (2) used to protect a passive chip containing data embedded in a device from remote skimming at a frequency which activates the chip to send the data, the shield (2) being removable to enable authorised reading of the chip data. The shield (2) is adapted to block the frequencies which activate the chip, the shield (2) further having a transmitter (18) which sends a coupling signal at a non- blocked frequency to a receiver (20), at least one of the receiver/and transmitter (18) having means to monitor the distance between the transmitter (18) and receiver (20) and an alert means to indicate when a predetermined distance has been exceeded.</p> |
