Tags and interrogators currently on the market communicate using a wide variety of air-interface protocols—the systems that govern how they communicate back and forth with one another. Tags that conform to EPCglobal’s ultrahigh-frequency (UHF) Gen 2 air-interface protocol standard can be killed. That is, they can be programmed to never respond again to a reader.
I think your question implies that a user would like the tags to respond to his/her commands, but to no one else’s. I am not aware of any protocols that would allow for this scenario. Certainly, you can lock user memory so that the tag would respond, but not allow you to read memory that has been locked. However, all tags respond to interrogators using the same standardized protocol.
In general, I think it would be bad if a tag did not respond at all, because then tags could be placed on objects or individuals, enabling others to track them without their knowledge. One privacy safeguard is that a tag can always be discovered if it is embedded in an object. (I’m referring here to commercially available tags. Who knows what spy agencies around the world might have developed?)
Perhaps RFID Journal‘s readers have insights into tags that can be programmed not to respond.
—Mark Roberti, Editor RFID Journal
How Can RFID Help Track Purchased Products? »