IBM Proposes Privacy-Protecting Tag

Moskowitz says he produced a prototype clipped tag using Alien's ALL-9338 Squiggle 1.1 tag and found that once the tag was clipped, its read range dropped from 2 meters (6.6 feet) to 5 centimeters (2 inches). He admits a clipped tag might require more time or materials to produce and, therefore, might cost more. However, he says, he has not yet discussed that possibility with tag manufacturers.

IBM says it is just now revealing the design to the wider RFID community, and researchers are still very early in the design and prototyping process. Therefore, the company believes it's too early to talk about any business strategy or licensing of the design, for which it has filed a patent.

RFID tags with a peeled-off layer: (A) tag with connected antenna, (B) peeled-off layer partly lifted.

The EPC Gen 2 Class 1 protocol includes a kill command, designed to address privacy concerns surrounding the threat of an unauthorized party surreptitiously reading tags. The kill command is executed by a reader and renders the tag unusable. The idea behind this command is that consumers could request merchants kill the tags attached to packaging or embedded in products they purchase. This also wipes out the ability of merchants or product manufacturers to use the tag for other purposes. Likewise, it would limit the consumers themselves from using the tag for future applications.

In an RFID Journal online poll conducted in May, 43 percent of respondents said the kill command is too radical a solution to privacy problems because it limits consumer applications. Another 43 percent said it is not too radical because it is the only way to ensure privacy. Thirteen percent said they were undecided.

Moskowitz notes that while consumers might request a tag be killed, they would have no visual proof any change had been made to the tag, as they would with a clipped tag.

"Also," says Moskowitz, "the kill command is weakly protected with a 32-bit password, which makes tags susceptible to sabotage, especially if all of your tags have the same password. And if you have a different password for all your items, then you, as the administrator of those passwords, need to manage [them all]."

Another idea suggested for addressing privacy concerns is a blocker tag, which can be placed near tagged items to confuse a reader and make it unable to read any item's tag (see RSA Security Designs RFID Blocker). Moskowitz notes, however, that to use the blocker tags, consumers would need to carry one with them at all times. Moreover, he points out that while tagged items can be placed in metallic bags designed to block tags from being read, some items are too large to store in such a bag.