RFID: To Tag or Not to Tag

Retailers love them, privacy advocates eye them with suspicion and some Christians think they're the "mark of the beast." For such tiny devices, RFIDs are stirring up huge controversies. But even as the tags infiltrate a range of things from clothing and pets to passports and license plates, confusion abounds over how the devices work, […]


But even as the tags infiltrate a range of things from clothing and pets to passports and license plates, confusion abounds over how the devices work, and what problems and advantages they bring.

Here are answers to some of the most common questions about this increasingly ubiquitous technology.

What is RFID?

RFID stands for radio frequency identification. A computer chip is attached to an antenna, and they are often referred to together as an RFID tag. Data stored on the chip transmits wirelessly through the antenna to an RFID reader or scanning device that operates on the same frequency as the antenna.

Are all RFID tags and readers the same?

Makers of RFID tags and readers use proprietary technology and design their systems to run on different frequencies (anywhere from 125 KHz to about 915 MHz). Tags designed by one company generally cannot be read by readers made by another company or by readers running on different frequencies. That may not be an issue in the future as industry standards are more broadly adopted.

RFID devices can be active or passive. Active RFID tags have a battery that provides power to transmit data on the chip, and can transmit data 100 feet or more. Passive RFID tags get their power from the RFID reader. When an RFID reader is directed at a passive RFID tag running on the same frequency, the reader sends an electromagnetic wave to the tag. This powers the tag to send data to the reader. Passive RFID usually requires a reader to be within a foot of the chip, but depending on the frequency, can be read from up to 20 feet away.

What's stored on the chip?

This depends on the storage size of the chip. Most RFID tags used by manufacturers to track products store only about 2 KB of data, which usually consists only of a unique serial number identifying the product. But RFID chips proposed for new electronic passports can store more data, such as a person's name, address, birth date and biometric data like a digital photo or fingerprint and iris scans.

What is RFID used for?

RFID tags store data about a product or person who carries the tag. The tag can be embedded in product packaging, in library books, in credit cards or in an ID badge or document, such as a driver's license or passport.

The tags can track products and pallets in warehouses and on store shelves. They're also used in electronic toll passes and key fobs. They've tracked cows and cadavers, and people are increasingly implanting them in pets. RFID chips have been embedded in bracelets worn by Alzheimer's patients, prison inmates and guards, and children in hospitals to make sure intruders don't abduct them.

Earlier this year, a California school required students to wear an ID tag embedded with an RFID chip to track their movements and monitor attendance. The move caused controversy, however, because the school neglected to tell students or parents that the badges contained a tracking device.

An implantable RFID chip, called the VeriChip, was recently approved by the Food and Drug Administration for security and health-care applications. The VeriChip is designed to be planted beneath the skin and would contain a serial number or password that medical personnel could obtain by scanning a patient's arm. The serial number could then be entered into a computer database to access a medical file set up by the patient.


Why is it becoming so popular?

Low-frequency RFID has been around for about 30 years, but it hasn't been practical for widespread use because manufacturing the chips and readers has been expensive. Also, a lack of standards that would allow any RFID reader to scan any chip kept the technology from being widely adopted, but proposed standards could help change that. Some RFID tags now cost less than 50 cents. Manufacturers like RFID because the technology is more convenient and durable than bar codes, which can be difficult to read if not passed directly in front of a scanner or if the bar code has faded or is torn on the product package. An RFID tag can also hold more useful information than a bar code, such as the expiration date of a perishable product like milk.

What are the concerns about RFID?

Privacy activists worry that RFID tags on individual products, rather than warehouse pallets, could track consumers inside and outside stores. Companies could collect information about customer interests based on where they go, especially if the serial numbers on tags are tied to an individual through purchases. Activists also warn that if tags are used widely in consumer products, police or FBI agents monitoring a political rally or religious service could scan a room with an RFID reader to determine quickly who is present or with whom the person carrying a tag associates.

What about using RFID on identification documents?

Activists are afraid an identity thief or terrorist could surreptitiously read the data on an RFID tag in a driver's license or passport and use it to create a duplicate document. Or an intruder could pick up data on a chip through "eavesdropping," which occurs when one reader picks up data as it is transmitted from a tag to another reader.

Can anyone hack an RFID chip to change information stored on it?

They conceivably could if the tag is a read-write tag as opposed to a read-only tag and the data stored on it is not encrypted. (Read-write means you can read data on the tag as well as write over or add to the existing data.)

What do RFID proponents say?

Businesses using RFID tags say they have no interest in gathering information on consumers and simply want to use the devices to increase efficiency and reduce data entry. They also claim RFID tags could be manufactured so they can be killed once they leave a store. It would also be difficult for law enforcement to obtain personal information about people based on RFID tags embedded in consumer products without having access to a store database that connects the data to a person. Data stored on ID badges could be encrypted to protect it from surreptitious scanning.

Does any legislation govern the use of RFID tags and information stored on them?

There isn't federal legislation specifically covering RFID, but other laws covering the privacy of data and law enforcement access to it would apply to RFID tags. Pending legislation in California would prohibit the use of RFID technology in state-issued documents, with some exceptions.

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