RFID

   

Radio frequency identification (RFID) is a method of remotely storing and retrieving data using devices called RFID tags. An RFID tag is a small object, such as an adhesive sticker, that can be attached to or incorporated into a product. RFID tags contain antennae to enable them to receive and respond to radio-frequency queries from an RFID transceiver.

History of RFID tags

Although some people think that the first known device may have been invented by Leon Theremin as an espionage tool for the Russian Government in 1945, the first real usage of RFID devices predates that. During World War II the United Kingdom used RFID devices to distinguish returning English airplanes from inbound German ones. RADAR was only able to signal the presence of a plane, not the kind of plane it was.

Perhaps the first work exploring RFID is the landmark 1948 paper by Harry Stockman, entitled "Communication by Means of Reflected Power" (Proceedings of the IRE, pp1196-1204, October 1948). Stockman predicted that " ...considerable research and development work has to be done before the remaining basic problems in reflected-power communication are solved, and before the field of useful applications is explored." It required thirty years of advances in many different fields before RFID became a reality.

Types of RFID tags

RFID tags can be either active or passive.

Passive RFID tags do not have their own power supply: the minute electrical current induced in the antenna by the incoming radio-frequency scan provides enough power for the tag to send a response. Due to power and cost concerns, the response of a passive RFID tag is necessarily brief, typically just an ID number (GUID). Lack of its own power supply makes the device quite small: commercially available products exist that can be embedded under the skin. As of 2004, the smallest such devices commercially available measured 0.4 mm × 0.4 mm, and thinner than a sheet of paper; such devices are practically invisible. Passive tags have practical read ranges that vary from about 10 mm up to about 5 metres.

Active RFID tags, on the other hand, must have a power source, and may have longer ranges and larger memories than passive tags, as well as the ability to store additional information sent by the transceiver. At present, the smallest active tags are about the size of a coin. Many active tags have practical ranges of tens of metres, and a battery life of up to several years.

As passive tags are much cheaper to manufacture, the vast majority of RFID tags in existence are of the passive variety. As of 2004 tags cost from US$0.40. The aim is to produce tags for less than US$0.05 to make widespread RFID tagging commercially viable. However, chip manufacturers supply of integrated circuits is not sufficient and demand is too low for prices to come down soon. Most analysts agree that a price level of less than $0.10 is only achievable in 6-8 years.

There are four different kinds of tags commonly in use. They are categorized by their radio frequency: Low frequency tags (between 125 to 134 kilohertz), High frequency tags (13.56 megahertz), UHF tags (868 to 956 megahertz), and Microwave tags (2.45 gigahertz).

See also for some Transponder devices which deliver a similar function, and contactless chipcards.

The RFID System

An RFID system may consist of several components: tags, tag readers, tag programming stations, circulation readers, sorting equipment, and tag inventory wands. Security can be handled in two ways. Security gates can query the ILS to determine its security status or the tag may contain a security bit which would be turned on and off by circulation or self-check reader stations.

The purpose of an RFID system is to enable data to be transmitted by a portable device, called a tag, which is read by an RFID reader and processed according to the needs of a particular application. The data transmitted by the tag may provide identification or location information, or specifics about the product tagged, such as price, color, date of purchase, etc. The use of RFID in tracking and access applications first appeared during the 1980s. RFID quickly gained attention because of its ability to track moving objects. As the technology is refined, more pervasive—and invasive—uses for RFID tags are in the works.

In a typical RFID system, individual objects are equipped with a small, inexpensive tag which contains a transponder with a digital memory chip that is given a unique electronic product code. The interrogator, an antenna packaged with a transceiver and decoder, emits a signal activating the RFID tag so it can read and write data to it. When an RFID tag passes through the electromagnetic zone, it detects the reader's activation signal. The reader decodes the data encoded in the tag's integrated circuit (silicon chip) and the data is passed to the host computer for processing.

Security gates can then detect whether or not the item has been properly checked out of the library. When users return items, the security bit is re-set and the item record in the ILS is automatically updated. In some RFID solutions a return receipt can be generated. At this point, materials can be roughly sorted into bins by the return equipment. Inventory wands provide a finer detail of sorting. This tool can be used to put books into shelf-ready order.

Current usage

2Low -frequency RFID tags are commonly used for animal identification, beer keg tracking, and automobile key-and-lock, anti-theft systems. Pets are often embedded with small chips so that they may be returned to their owners if lost. In the United States, two RFID frequencies are used: 125kHz (the original standard) and 134.5kHz, the international standard.

High-frequency RFID tags are used in library book or bookstore tracking, pallet tracking, building access control, airline baggage tracking, and apparel item tracking. High-frequency tags are widely used in identification badges, replacing earlier magnetic stripe cards. These badges need only be held within a certain distance of the reader to authenticate the holder.

UHF RFID tags are commonly used commercially in pallet and container tracking, and truck and trailer tracking in shipping yards.

Microwave RFID tags are used in long range access control for vehicles, an example being General Motors' OnStar system.

Some toll booths, such as California's FasTrak system, use RFID tags for electronic toll collection. The tags are read as vehicles pass; the information is used to debit the toll from a prepaid account. The system helps to speed traffic through toll plazas.

Sensors such as seismic sensors may be read using RFID transceivers, greatly simplifying remote data collection.

In January 2003, Michelin announced that it has begun testing RFID transponders embedded into tires. After a testing period that is expected to last 18 months, the manufacturer will offer RFID-enabled tires to car-makers. Their primary purpose is tire-tracking in compliance with the United States Transportation, Recall, Enhancement, Accountability and Documentation Act (TREAD Act).

Cards embedded with RFID chips are widely use as electronic cash, e.g. Octopus Card in Hong Kong and the Netherlands to pay fares in mass transit systems and/or retails.

Starting from the 2004 model year, a "Smart Key" option is available to the Toyota Prius and some Lexus models. The key fob uses an active RFID circuit which allow the car to acknowledge the key's presence within 3 feet of the sensor. The driver can open the doors and start the car while the key remains in a purse or pocket.

In August 2004, the Ohio Department of Rehabilitation and Correction (ODRH) approved a $415,000 contract to trial the tracking technology with Alanco Technologies. Inmates will wear "wristwatch-sized" transmitters that can detect if prisoners have been trying to remove them and send an alert to prison computers. This project is not the first such rollout of tracking chips in US prisons. Facilities in Michigan, California and Illinois already employ the technology.

Implantable RFID "chips", originally designed for animal tagging are being used and contemplated for humans as well. Applied Digital Solutions proposes their chip's "unique under-the-skin format" as a solution to identity fraud, secure building access, computer access, storage of medical records, anti-kidnapping initiatives and a variety of law-enforcement applications. Combined with sensors to monitor body functions, the Digital Angel device could provide monitoring for patients. The Baja Beach Club in Barcelona, Spain uses an implantable Verichip to identify their VIP customers, who in turn use it to pay for drinks. The Mexico City police department has implanted approximately 170 of their police officers with the Verichip, to allow access to police databases and possibly track them in case of kidnapping.

Potential uses

RFID tags are often envisioned as a replacement for UPC or EAN bar-codes, having a number of important advantages over the older bar-code technology. RFID codes are long enough that every RFID tag may have a unique code, while UPC codes are limited to a single code for all instances of a particular product. The uniqueness of RFID tags means that a product may be individually tracked as it moves from location to location, finally ending up in the consumer's hands. This may help companies to combat theft and other forms of product loss. It has also been proposed to use RFID for point-of-sale store checkout to replace the cashier with an automatic system, with the option of erasing all RFID tags at checkout and paying by credit card or inserting money into a payment machine. This has to a limited extent already been implemented at some stores[1] (http://www.ncr.com/repository/articles/pdf/sa_selfcheckout_integratedsolutions.pdf).

An organization called EPCglobal is working on a proposed international standard for the use of RFID and the Electronic Product Code (EPC) in the identification of any item in the supply chain for companies in any industry, anywhere in the world. The organization's board of governors includes representatives from EAN International, Uniform Code Council, The Gillette Company, Procter & Gamble, Wal-Mart, Hewlett-Packard, Johnson & Johnson, and Auto-ID Labs. However, most RFID manufacturers work towards ISO-classification 18000-6 in stead of EPC standardization. ISO-classification has a wider industry recognition and EPC is in principle only looking after the needs of retailers and Consumer Packaged Goods (CPG) companies.

In July 2004, the Food and Drug Administration issued a ruling that essentially begins a final review process that will determine whether hospitals can use RFID systems to identify patients and/or permit relevant hospital staff to access medical records. Update: According to the News Scan of Information Week on Oct. 18 2004, FDA has approved the country's first RFID chips that can be implanted in humans. The 134.2kHz RFID chips, from VeriChip Corp., a subsidiary of Applied Digital Solutions Inc., can incorporate personal medical information and could save lives and limit injuries from errors in medical treatments, according to the company. The FDA approval was disclosed during a conference call with investors.

Many somewhat far-fetched uses, such as allowing a refrigerator to track the expiration dates of the food it contains, have also been proposed, but few have moved beyond the prototype stage.

Other future application related with transport and safety is using the RFID as intelligent traffic signals on the road (Road Beacon System or RBS). The system is based on an onboard vehicle reader and RFID tags embedded under the asphalt, signalling the driver when passing over. The chips have a very low implementation cost and a fast field implementation. They require no maintenance and run without batteries. They can send any kind of information to the driver, from speed limits to position information. The onboard vehicle reader can be completely customized, the driver can choose the information he is interested on. Also, the driver can be informed or alerted depending on his preferences. As an example, a driver will probably switch off tourist information during business trips but will switch it on during vacation periods. Other possible applications are for high precision indoor/outdoor positioning systems, transport exploitation systems, logistics or as a law enforcement ally (black box auditing). More details in: [2] (http://www.roadbeacon.com).

Controversy

How would you like it if, for instance, one day you realized your underwear was reporting on your whereabouts? [3] (http://news.com.com/2100-1029_3-5065388.html) - California Senator Debra Bowen, at a 2003 hearing

The use of RFID technology has engendered considerable controversy and even product boycotts. The four main privacy concerns regarding RFID are:

  • The purchaser of an item will not necessarily be aware of the presence of the tag or be able to remove it;
  • The tag can be read at a distance without the knowledge of the individual;
  • If a tagged item is paid for by credit card or in conjunction with use of a loyalty card, then it would be possible to tie the unique ID of that item to the identity of the purchaser; and
  • Tags create, or are proposed to create, globally unique serial numbers for all products, even though this creates privacy problems and is completely unnecessary for most applications.

Most concerns revolve around the fact that RFID tags affixed to products remain functional even after the products have been purchased and taken home, and thus can be used for surveillance, and other nefarious purposes unrelated to their supply chain inventory functions. Although RFID tags are only officially intended for short-distance use, they can be interrogated from greater distances by anyone with a high-gain antenna, potentially allowing the contents of a house to be scanned at a distance. Even short range scanning is a concern if all the items detected are logged in a database every time a person passes a reader, or if it is done for nefarious reasons (e.g., a mugger using a hand-held scanner to obtain an instant assessment of the wealth of potential victims). With permanent RFID serial numbers, an item leaks unexpected information about a person even after disposal; for example, items that are resold, or given away, enable mapping of a person's social network.

Another privacy issue is due to RFID's support for a singulation (anti-collision) protocol. This is the means by which a reader enumerates all the tags responding to it without them mutually interfering. The structure of the most common version of this protocol is such that all but the last bit of each tag's serial number can be deduced by passively eavesdropping on just the reader's part of the protocol. Because of this, whenever RFID tags are near to readers, the distance at which a tag's signal can be eavesdropped is irrelevant; what counts is the distance at which the much more powerful reader can be received. Just how far this can be depends on the type of the reader, but in the extreme case some readers have a maximum power output (4 W) that could be received from tens of kilometres away.

The potential for privacy violations with RFID was demonstrated by its use in a pilot program by the Gillette Company, which conducted a "smart shelf" test at a Tesco in Cambridge. They automatically photographed shoppers taking RFID-tagged safety razors off the shelf, to see if the technology could be used to deter shoplifting. [4] (http://www.smalltimes.com/document_display.cfm?document_id=5363)

In January 2004 a group of privacy advocates was invited to METRO Future Store in Germany, where an RFID pilot project was implemented. It was uncovered by accident that METRO "Payback" customer loyalty cards contained RFID tags with customer IDs, a fact that was disclosed neither to customers receiving the cards, nor to this group of privacy advocates. This happened despite assurances by METRO that no customer identification data was tracked and all RFID usage was clearly disclosed. [5] (http://www.spychips.com/metro/overview.html)

The controversy was furthered by the accidental exposure of a proposed Auto-ID consortium public relations campaign that was designed to "neutralize opposition" and get consumers to "resign themselves to the inevitability of it" whilst merely pretending to address their concerns. [6] (http://www.spychips.com/press-releases/security_gaffe.html)

The standard proposed by EPCglobal includes privacy-related guidelines for the use of RFID-based EPC. These guidelines [7] (http://www.epcglobalinc.org/public_policy/public_policy_guidelines.html) include the requirement to give consumers clear notice of the presence of EPC and to inform them of the choice that they have to discard, disable or remove EPC tags. These guidelines are non-binding, and only partly meet the joint position statement (http://www.spychips.com/jointrfid_position_paper.html) of 46 multi-national consumer rights and privacy groups.

In 2004, Lukas Grunwald released a computer program RFDump which with suitable hardware allows reading and reprogramming the metadata contained in an RFID tag, although not the unchangeable serial number built into each tag. He said consumers could use this program to protect themselves, although it would also have significant malicious uses.

There are applications instead where using RFID technology inversely as usual generates no concerns about privacy. This is the case of the Road Beacon System (RBS) [8] (http://www.roadbeacon.com) where the user is the only one who is using the reader collecting RFID information embedded under the road. This information can be stored in a "black box" but it is only avalilable for him/her, and is not travelling over networks, mobile phones or the Internet.

Passports

A number of countries have proposed to embed RFID devices in new passports [9] (http://news.com.com/E-passports+to+put+new+face+on+old+documents/2100-7337_3-5313650.html), to facilitate efficient machine reading of biometric data. Security expert Bruce Schneier said of these proposals: "It's a clear threat to both privacy and personal safety. Quite simply, it's a bad idea." The RFID-enabled passport uniquely identifies its holder, and in the proposal currently under consideration, will also include a variety of other personal information. This would greatly simplify some of the abuses of RFID technology just discussed, and expand them to include, for example, abuses based on machine reading of a person's race or nationality. For example, a mugger operating near an airport could target victims who have arrived from wealthy countries, or a terrorist could design a bomb which functioned when approached by persons of a particular race.

Driver's Licenses

The US state of Virginia has considered putting RFID tags into drivers' licenses in order to make lookups faster for Police Officers and other government officials. The Virginia General Assembly also hopes that by including the tags fake identity documents would become much harder to obtain. The proposal was first introduced in the "Driver's License Modernization Act" of 2002, which lapsed without vote, but as of 2004 the concept is still under consideration by a committee.

The idea was supposedly prompted by the fact that several of the September 11 hijackers held fake Virginia drivers' licenses. However the American Civil Liberties Union has claimed that in addition to being a risk to privacy and liberty, the proposal in fact would not have hindered the hijackers, since all their false documents were valid, officially issued documents obtained for a false identity. That is, the current weakness in the system is not inspecting documents in the field, but verifying identities before issuing documents.

Under the proposal, no information would be stored on the tag other than a number corresponding to the holder's information in a database, only accessible by authorized personnel. Also, to deter identity thieves one would simply need to wrap ones driver's license in aluminium foil. [10] (http://www.cavalierdaily.com/CVarticle.asp?ID=21006&pid=1202), [11] (http://washingtontimes.com/metro/20041006-113607-9806r.htm)

External links

In the news

Opposition

Industry associations

Industry gazettes, journals and blogs

  • RFID Gazette (http://www.rfidgazette.org/), providing daily RFID-related news
  • The Future Is Here: A Beginner's Guide to RFID (http://www.rfidgazette.org/2004/06/rfid_101.html), an RFID Gazette essay. (June 2004)
  • RFIDbuzz: Website (http://www.rfidbuzz.com/) and Wiki (http://www.rfidbuzz.com/wiki/)
  • RFID Journal: Michelin Embeds RFID Tags in Tires (http://www.rfidjournal.com/article/articleview/269/1/1/)
  • RFID Log (http://www.rfidlog.com/), industry news service on RFID innovation, implementation and legal processes
  • RFID News (http://www.rfidnews.org/), weblog and monthly e-magazine covering the RFID Industry
  • RFID and Contactless technology News (http://www.contactlessnews.com/), free resource for breaking news and research on the use of contactless and radio frequency identification technologies. Profit, privacy, and the battle for control of the emerging technology are frequently covered topics in this industry leading resource.
  • MoreRFID.com (http://www.morerfid.com/), free RFID information site.
  • RFID Global Resource Link (http://www.byvalor.com/), a comprehensive directory for system integrators to have quick access to all global RFID-related resources.


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