RSA Security has announced that it's working on RSA Blocker Tag, an anti-radio frequency identification technology. The proposed tag is designed to prevent readers from accurately scanning tags on goods and reading their electronic product codes, or EPCs.

When development is complete, the blocker tags will work by "spamming" RFID readers that attempt to scan tags. Blocker tags will be active in the same short range as RFID tags, and must be in close proximity to a tag in order to block it. RSA demonstrated a software-based version of the blocker at its RSA Security conference.

The pharmaceutical industry is rapidly moving toward item-level RFID tagging of products, while consumer packaged goods manufacturers are testing pallet- or case-level tagging as they evaluate the advantages of tracking individual high-priced items such as Gillette's Mach 2 razor blades.

"In a naive, RFID-enabled world without technical forethought, there is risk that sensitive information could be visible in secret to anyone with an RFID reader," Burt Kaliski, director and chief scientist of RSA Laboratories, said in a statement. RSA is a founding member of EPCglobal, an industry consortium developing standards for the commercial use of RFID. It's the first technology company to openly admit that RFID could be used to invade consumers' privacy.

"Whereas retailers think about tracking inventory," Kaliski said, "privacy advocates worry about what happens when the RFIDs leave the store. It's up to companies like RSA Security to help bridge that gap."

Also on Tuesday, California State Senator Debra Bowen introduced SB 1834, the first national bill to propose privacy standards for the use of RFID. The activist Democratic senator from Redondo Beach wants legislators to require businesses or government agencies to inform people when they use an RFID system, get express consent before tracking and collecting information and detach or destroy RFID tags that are attached to a product before it leaves the store. Bowen chairs the Senate Subcommittee on New Technologies, which held two hearings on RFID technology and privacy.

Privacy activists say that neither killing tags when a product leaves the store nor the availability of blocker tags is enough. A recent position statement issued by Consumers Against Supermarket Privacy Invasion and Numbering (CASPIAN) and seven other organizations including the Privacy Rights Clearinghouse, American Civil Liberties Union and Electronic Frontier Foundation said that killing tags at the store exit doesn't solve the problem of tracking consumer behavior inside the store. The group fears the availability of blocker tags might encourage the proliferation of RFID by giving consumers a false sense of security.