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Privacy Technology

NYT on RFID 389

The New York Times has a piece on RFID tags. It's basic, but worth reading as a milestone - the technology is starting to enter the public eye. These RFID tags will have unique serial numbers - every RFID-tagged item you purchase will be uniquely different from every other nearly-identical item, enabling it to be identified and associated with you long after the purchase. And no, microwaving will generally not destroy the tags, and no, most items won't be microwaveable anyway. Try to microwave your couch.
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  • by ArsonPerBuilding ( 319673 ) <> on Monday September 29, 2003 @06:32AM (#7083180) Homepage
    You mean you don't have a jiggawatt microwave gun?

    That goes next on the list to a lime pit for all mad scientists.
    • So, what you do is go and buy something liable to attract FBI attention (large quantities of ammo, anarchist cookbook etc...), then go nail the RFID tag to the house of someone you don't like.

      I like the sound of this... *evil grin*
    • Why bother? Modify your microwave oven, fit a suitable horn to the magnetron output (made of tinfoil, what else?). Cheap and effective

      No responsibility whatsoever taken for the smell of kidneys frying (yours)

    • You mean you don't have a jiggawatt microwave gun?

      If you do have a microwave gun, please make damn sure you get the cat off the couch before you use it.
    • You know, RFID tags are a lot like cookies. When they were designed, the intent was to help a web site maintain state. A security mechanism was built in to prevent a web site from getting someone else cookie. Courtesy of and others, now they are used to track marketing and web site visits and clearly violate my privacy. Yet, I cannot browse the web without them because of how sites are designed to use them. This means that I have to periodically clean out cookies that are unwanted and v
    • What the hell's a jiggawatt?
    • Incidentially, gamma radiation will destroy rfid tags.

      Yes, I've actaully asked someone who would know.
  • Big Brother (Score:3, Interesting)

    by azbot ( 544794 ) on Monday September 29, 2003 @06:33AM (#7083184)
    But How does it benifit the end user, oh wait I don't have to wait as lon in the checkout line with five screaming kids and a trolley full of sofas
    • Not good. (Score:5, Interesting)

      by digitalunity ( 19107 ) <digitalunity AT yahoo DOT com> on Monday September 29, 2003 @06:59AM (#7083276) Homepage
      I have to admit, I can see why retailers would want to exploit RFID tags. It would save them a lot of money in labor, as well as reducing the load on any loss prevention manager. This boils down to either more profits or lower consumer costs.

      I have three opinions about them.

      1) Everything you buy that contains an RFID tag must be properly labeled. The consumer should know what they are buying.

      2) There should be a way to easily disable them after taking the product home. Ideally, they should be deactivated on your way out the door, but there are complications(non-technical) hindering the store's choices.

      3) Any product that has a unique characteristic or property shouldn't have an RFID tag. For instance, if I go to the local Sears, Home Depot, Lowes, whatever and buy a personal fire safe(w/o the changeable combinations), I wouldn't want the safe to have it's combination somewhere indexed to the RFID chip's serial number. There is a greater security risk here, this is but one example.
      • actually the consequences are much worse than hypermarketing. Imagine if you will an itemized list of everything you have bought. And a list of everything your friends have bought. Thomas jefferson himself couldn't help you if some overzealous DA gets it in his head that you and 6 people you know may have bought thing that 'could' be used to make a domestic terrorism device.

        I know there are some of the readers that will think I'm paranoid or a conspiracy nut. I want you to keep in mind the abuses of infor
        • Re:Not good. (Score:3, Interesting)

          by ninthwave ( 150430 )
          Which goes back to the Defense Department Funding this heavily in the article. Yes great for shipping but if they have the standard in play they have the readers.

          What we need is an open source RFID reader so we can identify the id tags we buy.

          Since the details of the tech is coming out we as a community need to respond make readers to read the tags. And then we can a isolate them by finding them and removing them from items or b create dummy tranmitters duplicating the id of items and place them in sill
        • Actually, I just want to know how big a window of opportunity I'm going to have to market my "RFID tag" frier before they illegalize 'em?
          Come ON folks. it generates a tiny amount of broadcast power by electromagnetic induction, right? just overload the damn thing. or arc it.
          Also: I can think of a couple of ways to read these in the hypothetical house I'm casing to rob;
          of course I don't have any actual hard data to work with, so its just a possibility...The first way involves setting up some reltively sensit
    • "But How does it benifit the end user, oh wait I don't have to "

      For that all you need is an ID thats unique PER PRODUCT, not PER INSTANCE OF THE PRODUCT.

      Its the individually unique ID thats the problem here, if it was like barcodes (identifying the product) it wouldn't be such a problem.

    • Re:Big Brother (Score:3, Insightful)

      by A55M0NKEY ( 554964 )
      No, but it might be wise to keep a bill of sale if you sell your sofa later on to someone. If that person ends up dumping the couch in a ditch somewhere, and the cops can look up the RFID in the master credit/debit card database and get your name, you might need the bill of sale saying that Joe College Kid bought it from you, to prove that the cost of it's removal shouldn't be billed to you.

      At least you won't have to register your couch with the DMV. You can always withdraw/use cash to remain anonymous,

  • Article - no reg. (Score:3, Informative)

    by Anonymous Coward on Monday September 29, 2003 @06:34AM (#7083188)
    How to Find That Needle Hopelessly Lost in the Haystack


    ew product tags equipped with microchips and tiny antennas could one day make it easy to scan all the groceries in a bag simultaneously, allow businesses to locate any item in a warehouse instantly and enable the Defense Department to better manage inventories of mundane necessities like meals and spare boots. Hitachi announced this month that it has developed tags so small that they can be embedded in bank notes to foil money launderers and counterfeiters.

    Tags with the technology known as radio frequency identification, or R.F.I.D., transmit a digital response when contacted by radio signals from scanning devices. Older versions of the technology have been around for decades, but now major manufacturers and retailers and the Defense Department are pushing to speed the development of a new version that could be read by scanners anywhere in the world, making it cheaper and more efficient to track the flow of goods from global suppliers to consumers.

    The Defense Department expects to issue a statement in the next few days calling on suppliers to adopt the new version of the technology by 2005. Wal-Mart Stores Inc. made a similar announcement in July when it said it was requiring its top 100 suppliers to place tags with the new technology on cartons and pallets shipped to its stores by the end of 2004.

    Radio frequency tags are currently used in products like wireless auto keys, toll collection systems and livestock and military armament tracking devices. A radio tagging system at Prada's store in SoHo in Manhattan identifies the clothes a shopper takes into a dressing room and allows the shopper to call up on an electronic screen images of the items being modeled and information about other colors and sizes.

    But as business's interest in the technology grows, so do efforts by privacy advocates to place strict limits on its use.

    "Very few people grasp the enormity of this," said Katherine Albrecht, director of Citizens Against Supermarket Privacy Invasion and Numbering, a group that was founded in 1999 to protest the use of frequent shopper cards and credit cards to collect data on individual consumers' purchasing habits.

    Ms. Albrecht and other critics say that companies and government agencies will be able to monitor what people read or where they assemble from radio tags embedded in their books or woven into clothing. Unlike bar codes, which cannot be scanned unless a laser has a direct line of sight to them, the radio tags can be read through walls, and multiple tags can be read in an instant.

    "R.F.I.D. certainly has value in the supply chain and in inventory management," said Beth Given, director of the Privacy Rights Clearinghouse in San Diego. But she added that "there are so many potential issues once it gets beyond the point of sale that consumer protections need to be written into law."

    Privacy advocates have suggested, among other things, that the tags be designed so that they cannot be reactivated once they are turned off, that all goods with a tag carry a consumer warning and that the tag must be removed when a product is sold unless the buyer agrees to leave it on.

    In theory, there may be benefits from keeping the tags active once a product is sold. Washing machines, for example, might identify the clothes in a load and automatically select the appropriate cleaning cycle. And a smart medicine cabinet could tract the expiration on drugs.

    Ms. Albrecht, however, has called for a one-year moratorium on using radio frequency tags on individual items while discussions about the implications of the technology take place.

    The privacy concerns have already caused some technology managers to play down their interest in using the tags. The Benetton Group, the clothing retailer, for example, announced in response to consumer protests that it had not attached the tags to any individual clothing items. And Wal-Mart halted plans for a widely publici
    • by Alain Williams ( 2972 ) <> on Monday September 29, 2003 @07:26AM (#7083376) Homepage

      • Privacy advocates have suggested, among other things, that the tags be designed so that they cannot be reactivated once they are turned off, that all goods with a tag carry a consumer warning and that the tag must be removed when a product is sold unless the buyer agrees to leave it on.


      1. We will remove it for you sir, but that will cost you 50c.
        How many will choose to leave it on.
      2. Why do you want to remove it sir, what have you got to hide ?
        And if you have something to hide, then that is just the excuse that the police/... need to come sniffing.

      Either way, the pressures will be such that most people won't bother/want to have them removed.

      • Answers to your questions....

        1. We will remove it for you sir, but that will cost you 50c
        Forget about it, I'll shop somewhere else.

        2. Why do you want to remove it sir, what have you got to hide?
        See answer to question 1
      • They'll have a rfid wand for $99.00 at the spy shop. You can then pull apart your expensive new fleece with tweezers to get the 12 rfids they wove into the fabric out, and ex-lax to get rid of the ones you ate.
    • by Tal Cohen ( 4834 )
      New moderation reason needed on Slashdot: "-1: Copyright violation".
  • Search and destroy (Score:2, Interesting)

    by warmcat ( 3545 ) *
    I should imagine the coils used by the RFID tags to get power and data should be detectable in the same way that metal detectors look for changes in their coil characteristics by the presence of the metal in the field. This should work even if the RFID tag is being quiescent waiting for a secret code to come in before it will talk, since it must suck power to listen.

    "Cleaning behind the couch" will get a whole new meaning.
    • Here's why I don't understand all of the complaints:

      For RFIDs to be exploitable in the way many seem to think they will be, and for them to be at all useful in a similar manner to bar codes for taking product inventory and the like, they're going to have to have a very generic way of checking the code. Otherwise the store is going to need several readers to check their stock, and the whole usefulness of the scheme will be lost.

      If they can read it easily, you can read it easily. It's just a matter of g

  • Power Source (Score:2, Interesting)

    No, I didn't RTFA, as it requires a requires a registration. My question is, how long do the power sources in these things last? The link to EPC global did not answer that question.
    • Re:Power Source (Score:2, Insightful)

      by L-s-L69 ( 700599 )
      RFID tags do not have an in built power supply, they are supplied with power by the scanner. IE scanner sends out pulse, tag responds. I know this is a bit simplistic but I hope it helps.
  • by pubjames ( 468013 ) on Monday September 29, 2003 @06:39AM (#7083207)

    Remember folks -- when you buy tinfoil, remember to remove the RFID tag from it before you make your hat.
  • by mrshowtime ( 562809 ) * on Monday September 29, 2003 @06:40AM (#7083210)
    Ha! I laughed at my buddy a few years back when he said that the U.N. could fly over your house and scan it to see how much money is in it. Now that is a reality. The RFID tags would be useful for inventory purposes, but the privacy thing is hard to shake. Who says that "advanced" criminals in the future won't develop a "super RFID scanner" and scan all of the houses in a neighborhood and "see" what goodies are in each house to try to figure out which house to rob. OR the government can use it to see which house is guilty of thought crime! :)
  • Airports (Score:2, Interesting)

    by Anonymous Coward
    Why aren't RFIDs used for baggage handling at airports? In Europe all baggage of a passenger has to be removed from the plane if this passenger does not board. This may lead to delays because they have to sift through every piece of luggage.

    RFIDs should make this much easier...
  • RFID detector (Score:4, Interesting)

    by Licensed2Hack ( 310359 ) on Monday September 29, 2003 @06:40AM (#7083213)
    We may not be able to stop companies from putting RFID tags on their stuff, which becomes *our* stuff when we buy it, but we sure as hell can find these tags and remove or destroy them after purchase.

    How difficult would it be to build your own RFID detector? If it is too difficult for Joe and Jane Average, how much might one cost at WalMart/Target/Walgreens/

    Somebody want to start a business making these? I have a manufacturing background...
    • You may be able to find and destroy the RFID tag, but you may also have to destroy or damage the item itself in order to get at the tag.
    • I'm wondering if RFID tech can't be used to our advantage - either by changing RFID tags to our own codes (almost sure this won't be possible, but hey, who knows?), or even just grabbing a bunch of *our own* tags to add to our stuff so we can do neat things like type "grep socks" and actually have it work. It's like William Gibson said: "... the street finds its own use for things."

      I suspect that detecting and removing most company RFID tags would be fairly straightforward, unless the company is being anno
  • I can see this happening the same way as Europe boycotts GM food, to the point where supermarkets may actually state on the product :-

    "This product does not contain any RFID tags"

    RFID can be harmless - for instance, helping supermarkets judge thier stock better, tallying up popular products etc.

    However, they are almost certainly going to be abused !
    • I doubt it'll go that quite way. Given the EU's track record I suspect we'll just have some legislation to the effect that the RFID has to be on a tear off strip or tag in the same way that labels are attached to clothing. Hell, the damn things are small enough that you could embed the things in those little sticky price labels if you were so inclined.

      Personally I'm looking forward to the day I can just wheel my trolley through a scanner and have a bill printed out automatically in front of the teller s

      • Your probably right.

        The general public will be blissfully unaware and non-caring about RFID, that is unless someone points out how it can get out of control.

        I suppose so long as there's strict legislation, for instance your 'tear off' tag idea, it won't be a privacy threat.

        The supermarket trolley idea is one that as far as I can remember has been through trial runs with different technologoy and indeed it's a good idea - except of course, it will mean millions of lost jobs worldwide ;)

        What would be cool
  • Oh no! (Score:2, Funny)

    by cperciva ( 102828 )
    My couch is going to have an RFID tag? But... that would allow people to track me everywhere I go -- I never leave home without my couch.
  • Bank notes (Score:4, Insightful)

    by Cyuonut ( 136786 ) on Monday September 29, 2003 @06:59AM (#7083277) Homepage
    ...embedded in bank notes to foil money launderers and counterfeiters.

    Would microwaving (whatsoever) the tag in a bank note render the note unusable? Will shops also have machines for automatically alerting the local police if I try paying with one of the forged ones?

    What if I, without knowing it, carry such a note?

    Guantanamo calls.

  • by thogard ( 43403 ) on Monday September 29, 2003 @07:02AM (#7083285) Homepage
    I'll worry about this when someone makes a reader that works well when several tags are in the field at one time. Currently farmers downunder are getting RFID tags for all their cows and most sheep. The farmers are sort of sold on a concept like Mr Spock's transponder saying Bessy is 126 meters at heading 74 with an arrow pointing at the cow. The problem is the current readers are good to read a cows tag at nearly .5 meters and when you consider how wide a cow is there is a bit of a problem.

    In an unrelated subject, if someone has any clue about RF and DSPs and pulling several cruddy analog low powered alalog signals out of the either, I know someone that would like to talk to you.
  • Blocking (Score:4, Informative)

    by phuqwit ( 102868 ) on Monday September 29, 2003 @07:05AM (#7083296)
    You have to start trust in the ingenuity of people ... RSA Security has already found a way to render RFID tags useless. []
    Privacy issues have surfaced because any reader can read the numbers on any tag. This means a reader in a department store, for example, could not only see what items a shopper has in her cart but could also see what other items she has purchased at competing stores, as well as how much money is in her wallet and what credit cards she's carrying.

    The technology that RSA Labs is proposing would make it simple for corporations and consumers to decide which tags could be read by which readers and when. The solution uses what's known as a blocker tag to simulate all possible tag serial numbers. In doing so, it prevents the reader from discovering whether a specific tag is present.
    Equipped with blocker tags it would seem that RFID tags become pointless once outside a controlled environment.
    • Nah, they'll just have to install Faraday cages in checkout lines so a person can go in and de-activate their RFID Blocker to pay without everyone knowing what they've got on them...

      RFID-embedded money - talk about a mugger's dream come true...
    • It would suck to have one of these at the automated checkout though.

      For one thing you have to wait forever for the plant sorry, checkout girl to find enough printer paper to print out every item for sale in the world.

    • Yeah, but given RSA's history with SSL licensing, *you* won't get to buy a blocker tag, only SuperMegaCorp (In minimum lots of 50,000). Sure they'll sell them to resellers, but how do you know that what the resellers are selling you haven't been tampered with (remember they're making these programmable with storage now... what if they sell an unblocker signal they've added to stores)?

      RSA makes some really cool stuff, but their licensing schemes for their intellectual property is heavily weighted against t
  • That sounds like a challenge. The first one to post pictures gets a karma bonus!
  • What would happen if ammunition was somehow RFID-tagged, in a way that survived firing?
    It would be a lot easier to tell who originally bought the ammunition for homicides, even if they didn't do any killing.

    Of course, right now the government has a guilty-til-proven-innocent attitude towards speeders they catch with unattended photo-radar traps. Will they take a similar stance if they know the owner of materials used in a crime?

    • If RFID gains more momentum, somehow I don't see criminals picking up bullets at Wal-Mart.

      But if you remember those stun-gun type personal protection thingers, if you fire one it releases thousands of tiny balls with a unique number on them that can be traced back to your weapon. Unfortunately, it's dodgy, because the ones I have heard about require that accurate records be kept at the point of sale, and the makers discovered that no such thing was going on, making the added security pointless. Maybe it
    • Ammunition CAN be reloaded. You can buy kits that do this. You can melt your own lead, pour it into molds and cast the bullets. Gun power and bullet primers can be purchased seperately. Bullet cases can be ordered via mail.

      I used to do this as a kid with my father. He still does it.
  • by dubstop ( 136484 ) * on Monday September 29, 2003 @07:18AM (#7083346)
    Dear Slashdot,

    Following some advice that I read on a popular website, I attempted to microwave my couch. In the subsequent house fire, I lost many of my prized possessions, and my microwave oven was damaged beyond repair.

    Do I have recourse to legal action in this matter?
  • Saving lives (Score:3, Interesting)

    by Frans Faase ( 648933 ) on Monday September 29, 2003 @07:19AM (#7083354) Homepage
    Not so long ago, we had a story here in the Netherlands where a shop was able to locate people who bought a certain item, which was poluted by someone wanting to damage a company, because these people had used a bonus card, with a unique number identifying them, and because the shop did register who sold what. Some people had become seriously ill after eating the contaminated product. Luckily, they all recovered.
    • Oh of freaking course privacy violations can be good sometimes.

      So what?

      Sometimes when I give money to the poor it gets embezzled. I once saw a television story about a corrupt cop. Sometimes, parents beat their children.

      What conclusions should I draw about these anecdotes, including your own?
  • Double charging... (Score:2, Insightful)

    by weave ( 48069 )
    OK, how do I stop from getting double charged for items? Like, I buy some books from Borders, then a week later walk into the same store with one or two of those books in my backpack? Or I buy a pack of smokes in one store, then walk into another one with that pack still in my pocket? Or buy some socks from BJs one week, then next week when I go there I'm wearing them.
    • by albin ( 52375 )
      Well, this is the exact type of use RFIDs are good for. Borders knows you bought that last week because the object is unique and is registered as sold in their database. And if the consumer protection groups are able to do what I think they will try to do, you will have elected to turn the RFID off at the point of purchase and they will have done so, for fear of you detecting it with your homemade RFID detector and suing them for invasion of privacy.
  • by Alain Williams ( 2972 ) <> on Monday September 29, 2003 @07:39AM (#7083424) Homepage
    If a manufacturer wants to stop resale of it's goods on the second hand market (think: CD, software, E-book) it says so on the packet and puts a unique RFID into every item.

    Then it goes round the car boot sales and picks up the items (doesn't even need to buy/touch them - scan as they walk by), tie back to the original sale (you did pay by credit card didn't you ?) and hit you with a court case.

    Result: more profit
  • by eclectro ( 227083 ) on Monday September 29, 2003 @07:51AM (#7083465)

    They are going to put these in tires. When you buy your tires the seller is going to be required to enter your information in a database.

    One day when you are going a little too fast in a school zone or run a yellow that switches to red too fast an underground computer is going to sense the rfid in your tire, immediately reporting the number via rf link to police headquarters.

    You would think that this would be for the purpose of giving you a ticket. You're right, you will get a ticket. But that is not the end the trail for your rfid number.

    It immediately gets sent to the state government where it checks to make sure you are not a deadbeat dad that the wherabouts of are unknown. Simultaneously sending it to the FBI to see if you are a name on the "patriot" act watchlist and indexes your location. If you drive on the same street on a regular basis they will know where to find you.

    You're not a deadbeatdad, lawbreaker, or terrorist you say??? Well the trail that your rfid number takes does not end there. Your rfid number is sold by cashed-strapped states to a commercial database under the auspices of "risk mitigation" that insurance companies subscribe to. Because you were speeding, you are at an increased risk and your car insurance rates are subsquently raised. Because you drive dangerously, your health insurance rates are also raised. Maybe they cancel your policy outright.

    You're thinking I'll just remove the rfid. No you won't. Driving with unregistered tires is against the law, and if the police can't scan you as you drive past his cruiser he pulls you over and immediately suspends your license and impounds your car. But you won't be able to remove it anyway, without destroying the tire, as it is purposefully integrated with the "steel belt".

    Does the trail end for your rfid tire number now? No, it most certainly doesn't. To see where it leads further, you are going to have to talk to my patent attorney.

  • I can see a market for fake RFIDs (did anybody think this won't happen). After all, those fake Guccis wouldn't be worth anything if they didn't let you pass muster at that exclusive club you are trying to get into.
  • by cat_jesus ( 525334 ) on Monday September 29, 2003 @08:11AM (#7083572)
    You don't have to disable RFID tags to screw with the data collection and tracking systems. If you are able to find and collect RFID tags you can carry them around with you wherever you go. Imagine having three or four car RFID tags on you as well as about a hundred refridgerator RFID tags. Dumpster diving for RFID tags would be great fun. You'd have tags from stuff that never really led back to you and would confuse the hell out of anyone trying to make sense of the history of the items. You could do things like remove all of the RFID tags from your clothes and keep only one RFID tag in your wallet that was from a pair of underwear. If anyone looked at the data they'd think some guy in the same pair of underwear he's been wearing for weeks is walking around carrying a few cars and a bunch of Refridgerators.

    This would be much more fun than filling our frequent shopper cards with bogus information or completing surveys with ridiculous answers.
    • Oh to have your life where filling out frequent shopper cards is a primary of significant entertainment.

      And here I am cursed with a life full of outdoor thrills, wine with good friends, excellent movies and various degrees of romantic entanglement.

      I really have been missing out on the good things. Thank you for opening my eyes.

    • While I very much agree with your operation chaos philosophy, I'm sure if RFID tags get suitably integrated into our society/economy, it will become a crime of the same order as any other identity manipulation, or worse, meshed in with DMCA, since you'd be manipulating a device's security features without authorization.

    • Na, the automatic doors at the supermarket won't open unless you have RFID tags for at least a shirt and shoes.
  • This is a snippet from my /. journal [] entry:
    "Barcode Scamming" -- How RFID could save us all

    The problem with barcodes is how easy they are to create, or more importantly how easy they are to forge. All one must do is download a standard UPC barcode font from the internet and install it on their home computer.

    An individual could walk into a store and write down the UPC code off of - lets say a 15" flat screen monitor that costs $245. This would-be criminal then goes home and prints up a UPC code o

    • "...Our criminal then returns to the store, places the label on a 21" flat screen computer monitor that retails for $995 and proceed to the checkout counter."

      The product name flashes up on the till, thats how the cashier knows you bought a flat screen TV and not a normal one.

      As for the detergent, the barcode IS PART OF THE BOX not stuck on afterwards. So as soon as they reach for the box they know you stuck your own barcode on it.

      "Consumer privacy advocates are concerned that the technology could be abus
      • But it does hold up.

        In Utah, there was an individual that was taking barcodes from 15" flatscreen monitors - printing them out on labels then returning and purchasing 19" screens.

        On the first go-around, the criminal bought 7 monitors without raising suspicion. The second time, he bought 8.

        The second time, the cashier was a bit computer savvy. The cashier stated "WOW, thats a really good price on flat panel screens." and later that day went to purchase one of those screens for himself. It rang up for $99

    • Consumers aren't stupid; they'll steer clear of retailers that keep track of too much of their personal information.

      You gloss over one of the major problems with the privacy debate here. How do you propose customers do this? No "privacy market" like you imply can develop in the current environment, because none of the prerequisites for a market has developed. People don't know what is being done with their data, don't realize how much value is being stolen from them (privacy-sensitive data is economicall
  • by ajs318 ( 655362 ) <`sd_resp2' `at' `'> on Monday September 29, 2003 @08:23AM (#7083621)
    The RFID chip works in conjunction with a tuned circuit {capacitor and coil; the coil also behaves as an antenna} that extracts energy from an applied RF field. The resonant frequency of this tuned circuit is the operating frequency for the system. The size of the coil determines the operating range. An RFID device with integral tuned circuit measures about 20mm. by 10mm. by 2mm. and has a range of a few cm. A smaller device would require an external coil, but the bigger coil would extend the working range.

    The transmitter feeds an RF power amp with a sensitive ammeter in one of its power supply leads.

    Now, when the tuned circuit is brought within range of the transmitter, it will pick up the signal. But that is all. A voltage will be induced across the system, and a current will flow, but they will be out of phase. When the voltage is at a peak, the current is nil, and vice versa. Recall that power = voltage * current, so there is no power. Bringing the tuned circuit into range of the transmitter will not affect the ammeter reading.

    However, if you connect a resistance across the two ends of the tuned circuit, then the current across this resistance will be in phase with the voltage. Energy is now being changed from electromagnetic waves to heat. And, strictly in accordance with the first law of thermodynamics, the reading on the ammeter will go up. Reduce the resistance and it will go up more. Of course, the imperfect coupling from transmitter to receiver itself behaves like a big resistance, which effectively limits the power available for the receiver {and therefore the ammeter swing}.

    Anyway, if we switch this resistance in and out of circuit, we can watch the ammeter moving in sympathy with the switching.

    The RFID tag gets its power by rectifying the AC induced in the tuned circuit, and using this to charge a capacitor. This capacitor stores enough energy to allow the tag to miss a few cycles, because it unavoidably will as a consequence of how it works. The tag then switches on and off a transistor which sits across the bridge rectifier {a transistor only conducts in one direction} in accordance with a predefined pattern. When the transistor turns on, more power is drawn from the transmitter. {As a side effect, the voltage is pulled down and the RFID tag has to rely on the capacitor contents to keep in this state, remember how far through the sequence it is, and so forth; so this state lasts only a few cycles}. The transmitter can see, by measuring the supply current to the RF power amp, whether the transistor in the RFID tag is on or off.

    The external RF field also provides a stable timing reference to the tag, because it can count cycles accurately and dead-reckon a few cycles when it has to.

    So, we have a one-way communication from the RFID tag to the transmitter, even though the RFID tag has no power supply of its own. If the RFID tag is absent or high resistance, this is a zero. When the RFID tag goes low-resistance, the transmitter can see this as a one. This allows us to send a binary number from the RFID tag.

    All the RFID tag does, once it comes into range of the transmitter, is continuously send out a series of zeros and ones by going low and high resistance. It is up to the transmitter to spot the resistance of the remote end.

    It is also possible to send data to the RFID tag, by switching the RF field on and off. While this could be used for programming of tags with serial numbers {instead of laser etching as is currently done}, it would require the tag to have some sort of EEPROM or Flash memory. These devices currently have a high power demand making them unsuitable for operation on RF power alone, but recall Clarke's first law: When a scientist says something is possible they are usually right; when a scientist says something is impossible they are usually wrong. So it is almost certain that future RFID tags could be reprogrammable.

    The canonical method for deactivating
    • It is also possible to send data to the RFID tag, by switching the RF field on and off. While this could be used for programming of tags with serial numbers {instead of laser etching as is currently done}, it would require the tag to have some sort of EEPROM or Flash memory. These devices currently have a high power demand making them unsuitable for operation on RF power alone

      Actually, there are read/write RFID tags on the market now. They're more expensive than read-only tags, obviously.

      Contactless s

  • An RFID scanner, a small portable application, and I can inventory the contents of my house and get fair insurance in a couple of hours.

    Not to mention tracing stolen couches.

    I got burglared a month or two back, and ripped off by the insurance last week, and this is one application I could go for.

    Presumably there will be a market in removing RFIDs from objects, but it's like serial numbers on cars and computers and mobile phones: do you really object that someone, somewhere, knows your taste in cars? For
  • I can just see these things used for public advertising like in Minority Report. "Hello Joe Blow, I see you just purchased some preparation H. Wouldn't you like to consider some non-invasive surgery? Just come on down to Frank's A Shack Today!".
  • My Couch? (Score:3, Insightful)

    by telstar ( 236404 ) on Monday September 29, 2003 @09:21AM (#7083936)
    "Try to microwave your couch."
    • Chances are if they're close enough to pick up the signal from the couch, they're already in my apartment, and can get a lot more information about me than which Sears I shop at.
  • I can't wait for the first peckerhead to get caught and fined for dumping his couch in the woods because an RFID tag in the furniture was tracable back to him. People dump a lot of junk in the woods... I wonder how many of them will be aware of the RFID tags that will point right back to them. And you'd better hope that your garbage collection service is on the up-and-up, too, or someone might end up accusing you of dumping your junk in the woods.
  • The Defense Department expects to issue a statement in the next few days calling on suppliers to adopt the new version of the technology by 2005.

    The Defense Department?? What did I miss?
  • long range rfid (Score:3, Informative)

    by I8TheWorm ( 645702 ) on Monday September 29, 2003 @09:42AM (#7084103) Journal
    How many folks that are paranoid about rfid tags currently own and use a cell phone? Or have a discount card from their grocery store?

    The longest range I know of on RFID (I write code for a company that implements wireless solutions, mostly in warehouses) is almost 20 ft. And that's at very high frequencies (14MHz, with active tags (they're quite a bit more expensive) and using lots of power (up to 60w). Texas Instruments [] makes a decent one, but so do the likes of Brady, Symbol, etc... This is nothing new...

    Besides, they're just tags. Removable. If you think someone is going to be watching your purchased items, throw the tag away. Fairly simple really.

    But if you have no cell phone, wear aluminum hats, etc... you could always make your own furniture...
  • I'm sick of every new (or repurposed) technology being hyped/justified by this type of tripe: "Imagine a that can automatically . This was supposed to happen with all kinds of appliances so far but there's damn little of that stuff available. The argument is usually a red herring. Imagine a washing machine that will automatically select the right setting to wash clothes. My ass. What does it do if I put permanent press in with heavy cotton (reading off my washing machine, I don't know what the fuck t
  • Try to microwave your couch.

    Bad idea: the metal springs overheat, and scorch the stuffing. Always use a conventional oven when cooking your couch!
  • So the microwave won't work. (I tried and the couch just won't fit).

    My new (patent pending) solution is the drive through RFID wash. Take your ordinary car wash, remove the hoses brush and crap. Install lead shielding and an EMP generator []. Put your tires, sofa and clothing on the cart and when it emerges from the other end no more peskey RFIDs.

    I can see a market for a Home EMP Kit [] as well. (The warning label reads, "Do not use near TVs, Computers, Pets, or Reproductive Organs".

  • RFID tags can help control inventory, improve product safety, and help business manage the flow of goods. All of these things end up being good for the consumer because it all helps to control costs. Yet RFID could be used to invade the privacy of individuals. I do not think you could drive past someone's house and determine what kind of appliances they have, the output is too low for that but, you could scan them and inventory them as they walked through a door or other checkpoint.

    I think this means th
  • C&C: Zero Hour (Score:3, Interesting)

    by delus10n0 ( 524126 ) <> on Monday September 29, 2003 @11:22AM (#7085013) Homepage
    I just bought the C&C expansion pack, Zero Hour, and inside the CD case itself (behind the front label) was affixed the standard little rectangle (to trip sensors in case you try to steal the game) but underneath it was a 1.5x1.5 RFID patch. This is the first time I've seen an RFID tag used for videogames..

%DCL-MEM-BAD, bad memory VMS-F-PDGERS, pudding between the ears