The pair behind the "RFID-Zapper", Tim and Chris (who don't reveal their last names online), say the gadget is designed to deactivate (destroy) passive RFID-Tags permanently.

Goals are a proof-of-concept and the construction of at least one functioning and appealing prototype, as well as a documentation of the project. The pair plan to publish the instructions for build online, "so that everyone can build an own RFID-Zapper".

"We have to expect to be surrounded by RFID-Tags almost everywhere within the near future, and they will serve many different purposes," write Tim and Chris online.

"The benefits and risks of this technology and its use are already being discussed.

"However, there will be atempts to use RFID-Tags to establish constant surveiliance and to further threaten and compromise the privacy of customers (and citizens and even non-citizens, when [governments] start to use RFID-Tags like the German [government] already did).

"To defend yourself against such measures, you might want a small, simple and relatively appealing gadget to permanently deactivate RFID-Tags around you, e.g., to deactivate RFID-Tags in recently bought clothes or books without damaging those [items]."

How does it work?

There are several ways to deactivate RFID-Tags, including RFID-deactivators, which send the RFID-Tag to sleep.

"A problem with this method is, that it is not permanent, the RFID-Tag can be reactivated," write Tim and Chris.

"Several ways of permanently deactivating RFID-Tags are know, e.g., cutting off the antenna from the actual microchip or overloading and literally frying the RFID-Tag in a common microwave-oven, which needs to be turned on only for a short period of time.

"Unfortunately both methods aren't suitable for the destruction of RFID-Tags in clothes: cutting off the antenna would require to damage the piece of cloth, while frying the chips is likely to cause a small but potent flame, which would damage most textiles or even set them on fire."

The RFID-Zapper copies the microwave-oven-method, but on a much smaller scale.

The duo modified the electric component of a singe-use-camera with flash, readily available in most retail outlets, to "keep the costs of the RFID-Zapper as low as possible".

The coil is made from coated copper wire and placed inside the camera where the film normally lies.

"Then one end of the coil is soldered to the camera's capacitor, from which we earlier disconnected the flash," Tim and Chris write.

"The other end of the coil is soldered to a switch, which itself is connected to the capacitor's other terminal. Once everything is tested, the camera can be closed again and henceforth will serve as a RFID-Zapper, destroying RFID-Tags with the power of ordinary batteries."

The zapper generates a strong electromagnetic field with a coil, which, claim the inventors, should be placed as near to the target RFID-Tag as possible.

The RFID-Tag then will receive a strong shock of energy comparable with an EMP and some part of it will blow, thus deactivating the chip forever.

Until now the pair have only had access to 13.56 MHz RFID tags, but hope to be able to test the RFID-Zapper on other tags soon.

A German privacy advocacy group — FoeBuD — plans to manufacture and sell a device that consumers could used to disable RFID tags permanently. FoeBuD says it wants to manufacture the RFID-Zapper and sell it at its online store. The group met with a hardware developer last week, but says it has no timescale for production or product price yet.