HOWTO kill/block an RFID

Instructables have just published their latest installment in their series of HOWTOs inspired by my forthcoming novel Little Brother, a young adult book about kids who use technology to wrest liberty from the Department of Homeland Security. This week, it's HOWTO block or kill an RFID chip.
-The easiest way to kill an RFID, and be sure that it is dead, is to throw it in the microwave for 5 seconds. Doing this will literally melt the chip and antenna making it impossible for the chip to ever be read again. Unfortunately this method has a certain fire risk associated with it. Killing an RFID chip this way will also leave visible evidence that it has been tampered with, making it an unsuitable method for killing the RFID tag in passports. Doing this to a credit card will probably also screw with the magnetic strip on the back making it un-swipeable.

-The second, slightly more convert and less damaging, way to kill an RFID tag is by piercing the chip with a knife or other sharp object. This can only be done if you know exactly where the chip is located within the tag. This method also leaves visible evidence of intentional damage done to the chip, so it is unsuitable for passports.

-The third method is cutting the antenna very close to the chip. By doing this the chip will have no way of receiving electricity, or transmitting its signal back to the reader. This technique also leaves minimal signs of damage, so it would probably not be a good idea to use this on a passport.

-The last (and most covert) method for destroying a RFID tag is to hit it with a hammer. Just pick up any ordinary hammer and give the chip a few swift hard whacks. This will destroy the chip, and leave no evidence that the tag has been tampered with. This method is suitable for destroying the tags in passports, because there will be no proof that you intentionally destroyed the chip.

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  1. Thanks!!

    Excellent post, RFID should stay where it was intended, in warehouses and production lines!

  2. I wonder if people that talk about RFID have ever tried to actually read RFID tags with normal (commercial)readers. I can say by experience that current passive RFID tags’ read success depends a lot on the environment. If you have, say, your RFID enabled passport on your pocket, unless somebody uses a pretty potent antenna in the right orientation or puts the antenna very close to your pocket, that tag won’t probably be read successfully (and writing is even harder). I say this because it seems that people think that if you carry your passport (or other RFID-enable stuff) around anybody can pretty much read its information with not much effort, and that’s simply not the case. However, I do agree that for this particular type of application other technologies (such as contact memory) are more suitable to avoid security problems.

  3. I say a bunch of people getting together and hitting their passports with hammers would make some pretty good performance art.

  4. What year did they start putting RFIDs in passports?

    Also: what would happen to you if you tried to get on a plane with a nonfunctional RFID in your passport? Given the state of things, I doubt they’d believe it was an accident, and even if it was they’d probably use it as an excuse to ‘vanish’ you for eight hours into an interrogating room anyway.

  5. Vorpalsword, according to wikipedia, they started putting them in US passports in 2006, though if you happen to be from Malaysia, 1998 is the date you’re looking for.

  6. Toplus, it’s a crime of opportunity. The ne’er-do-well generally doesn’t care about targetting a specific person – any rube will do. So he just has to target a large enough crowd with a covert reader and whilst it’s unlikely he’ll get everyone, he’s still likely to get *someone*. Pretty much like a guy with a gun randomly firing in the general direction of a crowd. And the person who gets hit is going to have a generally crappy time thereafter in either case.

    I’d rather have the option to remove the risk entirely.

  7. Liquids and metal impede RFID readers. One could make a foil packet to keep one’s passport. If you had time and a lot of ingenuity, you could make a passport sleeve with water in between two layers.

  8. There is also the idea that the technology will probably improve over time as it is used in more environments. I wouldn’t want to bet that nobody will develop a better tag or more sensitive scanner and assume that I am safe sticking my passport in a tinfoil sleeve. Crushing the silicon sounds like much more robust option.

  9. The last non-chipped passports were produced a couple of months ago. I don’t know how long it will take DOS to work them through the system, though.

    I also have to add that if you had seen the things that people do to their passports just through ordinary abuse, signs of physical damage would not necessarily be a red flag. Just make sure you do something relatively conservative, like run it over with a truck or shoot a bullet through it.

  10. There are a number of companies advertising sleeves and wallets, running in the $10-$25 range, faraday cages and the like. Are these any good? If they work, it seems a good solution. You could take your passport out of the sleeve when it was time to do the scanning reducing the chances that some officious numb nuts would hold you up in your travels.

    My passport was issued in September 2006. As I understand it, that means it might be one of the chipped ones. I do not like that, not one little bit. How can I tell? Where are the chips installed in passports? Front cover, back cover, in the center, a corner?

    If these sleeves work and if my passport does indeed have a chip, I might well consider buying one. As angry as I am about the fact that these were installed (and that the US citizenship couldn’t be bothered to interrupt their shopping and television viewing to take a stand on this and other issues) I would like it if there was a way to deal with this that didn’t entail breaking the law.

  11. I just wanted to point out that the picture is of an RF security tag, not an RFID. It’s just a simple Inductor-Capacitor circuit, and there’s no computer chip.

    The difference between that and and RFID is that the RF security tag is not uniquely identifiable, and it’s trivially easy to burn out the capacitor using an EM field tuned to the resonant frequency of the circuit (which is how the cashiers deactivate it).

  12. Would a magnet work? I’ve got some pretty strong rare earth magnets that I imagine would do the trick. Just rub the part of the passport containing the chip between two of those magnets should work. Does anyone have any experience with this?

  13. if someone hit me on the back of my neck with a hammer, they’d break more than my rfid chip!



  14. My passport was delivered in mid March of this year, and contains an RFID.

    The passports that have RFID tags inside also bear a little insignia on the front cover of the passport indicating “sensitive” electronics inside. The insignia looks like a mini (non-US) flag the same color as the gold lettering on the front.

  15. All well, and good to hit, stab, microwave these chips, but how about a tutorial to actually find these things.

    I just recieved a new debit card that I’m sure has one in it. Now for the life of me, I can’t figure out where exactly it would be. Maybe on passports its more obvious, but not on my card. I don’t just want to bash randomly with a hammer at it. I would like to use this card because they actually managed to spell my name correctly on it, unlike my old one.

    And to those that are upset that Cory is pluggging his book on what basically amounts to his website (in part I know): God forbid that someone is allowed to make a livelyhood.

  16. #20:

    If your debit card has an RFID chip in it, it is pretty easy to find. Just hold your card up to the light and look at the reflection off the face (and the back) of the card. The RFID chip will be a pea-sized rectuangular indentation.

    On my Chase Freedom, it is located in the top half of the “H” in Chase as shown by the yellow square in the below image:

    I would imagine that the placement doesn’t vary too much from card to card. Disabling it would probably require a finishing nail or something smaller than a hammer.

  17. Thank you so much for that incredibly techno-savy knowledge. Without it, I could never have figured out how kill an RFID.

    Its so extremely complex that I might have to practice the procedure on some small animals to get it right.

    Does anyone know if these methods work for killing other complex devices?

  18. How do I confirm that it’s active before I hit it, and inactive afterwards without going shopping? I want to know that I’ve hit it enough, or hard enough, or in the right place, but I don’t want to buy specialist equipment.

  19. I’d worry more about the ability of [insert powerful entity name here] to have your cell phone company keep a log of your movements, good down to a meter or so, for as long as they care to. And don’t believe for a second you can shut it off with a menu selection, not if they don’t want you to. And I find it curious that on, say, an iPhone for example, the precedent has been set for a battery that you cannot disconnect voluntarily. If I were a suspicious type, I would go so far as to say that they are moving towards, quietly, a GPS tracking system that you cannot depower even if you turn the phone off.

  20. My passport recently survived a trip through the washing machine (and dryer). I wonder if that’s enough to damage the stupid thing.

    I will probably confirm breakage via a hammer tonight. Thank you for posting this, it seems ridiculously obvious but I’d never considered that they could be so easily disabled.

  21. Not to mention that contents will be encrypted and it’ll be pretty hard to decode the contents provided you don’t have proper keys…

  22. “Does anyone know if these methods work for killing other complex devices?”

    I think hitting any complex device with a large enough hammer should work.

  23. To paraphrase a certain vampire killed: “You’d be surprised how many things you can kill by hitting with a hammer.”

  24. This is all good to know, but aren’t RFID chips extremely small? Where exactly is the spot that has to be hit with the hammer? Can you find the chip just by looking for it?

  25. Enochrewt,

    The name is buttseks, feel free to type it out (gives me a warm fuzzy feeling).

    Since when do I have to be upset about something to make fun of it?

    Also, try a stud finder…an awesome stud finder.

  26. PASSPORT! CRAP!! Mine expires in October and I’d better get the paperwork for the renewal in NOW or risk being hassled at the Canadian border even more massively than usual.
    Regarding the disabling of the chip, I’m sure an electrical arc of sufficient strength sent through the thing would also scramble its brains while leaving zero evidence of tampering. I’d use a needle probe gently poked into it from either side and increase the voltage between them until a little current flowed. Depending on the dielectric strength of the material anywhere from 1kv to 10kv should do it. It would be subtle and effective though lacking the visceral pleasure of a good whack with a mallet.

  27. @17: You make it sound as if it’s a bad thing that a person would talk about their own published work on their own blog.

    Oh noes! Cory Doctorow wrote a book and he’s using his own blog to point out that part of what he wrote about is easily a reality, run for the hills!

  28. Tangentially related, WTF is the deal with “you can’t use your passport if it’ll expire within six months”? I’ve evidently been misusing the word “expires” for years to mean “the document is useful up until this date”.

  29. @#27: “This company has a video demo of their protective sleeves:”

    Or you could put it in an old Doritos bag, for the same effect

  30. Due to greatly increased demand and an inexcusable failure to scale up the passport issuing processes, it can take months to get a passport. Half-year waits have been reported. Renewals are said to be quicker but I’d recommend anyone who really needs a current passport to take no chances with the timing.

  31. The chips or antennae in RFID tags are not really that small. Check out the wide array of tags available:

    There was some PR stuff a few years ago about a company that was trying to miniaturize RFID to the size of grains of sand. Not sure what the progress is on that.

    The RFID industry is full of PR and other stuff too.

  32. My passport solution is my favorite, but unfortunately unreproducible now: When I heard they were putting RFIDs in passports, I renewed before the switch. I have a passport that’s good for another 9-ish years with no RFID.

  33. If you’re going to smash the RFID with a hammer, make sure to place a towel over it so you won’t leave crosshatch indentations on the passport.

  34. destroying the RFID in your passport just seems like a good way to bring down more hassle upon yourself at the airport. if you’re that worried about it, use one of those special sleeves (yes, a Doritos packet will do fine too… they just tend to be greasier and are rarely the right size).

  35. if they chip them in exactly the same place, it should be easy to build a jig with a spring loaded punch that precisely crushes them. Could set up a little booth at the airport.

  36. Yup. Doorknob caps and microwave oven diodes. The oil burner transformer is a static xfmr designed to deliver very little current. Other options: HV transformer from a color TV (30KV) or the PSU from an old tube type O-scope. I’ve got a moudering pile of those.

  37. If you’re worried about a fire, put it in a microwavable casserole dish before you nuke it.

    I lit a pack of gum on fire in the microwave once, trying to thaw it. That was sort of stupid of me. But anyway, it wasn’t a big fire and no one found out…

  38. I saw video clips. I saw ads. What I want is for youse guys who know more about matters electronic if any of these things are worth a damn or not, and why.

    Cripes, if you were to need some little creepy crawly thing IDed, I’d step right up and help. I’m just looking for a little advice here.


    @ # 51, who freezes gum?

  39. I’ll need a stack of passports to perfect the technique on. Any corrupt civil servants out there?

  40. I’m thinking that a strong localized magnetic field should induce enough current in the chip’s antenna to scramble its brains. Suitable devices might include demagnetizers used in watch repair and laboratories, ‘growlers’ used for finding shorted coils in motors a large solenoid or anything with an AC coil and an air gap. I spend most of my time finding ways to fix electronic stuff, but RFID is one device I don’t mind looking for ways to ruin.

  41. As an industrial engineer, the first time I heard of RFID devices, all I could think of was, thank heavens, because I had always dreamed of such a tool. But now that our government has accepted the idea as a means to track livestock, I am so against it that I would commit to violence before I would accept their programs using it because all they want to do it track us the people and frankly that’s none of their damn business. I’ve accepted that our government is corrupt and evil and that none of them have ever read our constitution or the writings of the country’s forefathers that wrote and agreed to this document. All I seem to here is that the constitution is an archaic document. But that is so wrong. It is truly a document for the ages.

  42. @#37 Crazy but true–several years ago I was almost denied entry to Costa Rica because my passport was going to expire in six months. At least this was the reason the official at the airport gave ….

  43. I founded Identity Stronghold. A company that makes RFID blocking sleeves and badge holders.

    You can block the signal with simple aluminum foil wrapped around your passport, credit card, drivers license, or transit card. The only problem is foil rips easily. That is why we made a Tyvek backed shielded sleeve. It can tear or puncture and lasts in your wallet for a long time.

    If you do kill the RFID chip in your passport you will likely have to go to the end of the LONG line at the airport. They can tell by the mark on the front cover that it is supposed to have an RFID chip readable.

    I have microwaved a Chase Blink card. It WILL destroy the chip but beware. In 5 seconds I saw a lightning bolt hit the card, then a blue torch like flame traced a beautiful brown melted rectangle around my card where the antenna is. You will end up with a nice burn mark on the glass plate in the microwave and the mag strip will be useless too.

    Please check out our products on our website That way you won’t have to bother ruining your microwave or ending up in the long line at the airport.

    Feel free to call us with questions. We are happy to give out any information we have.

    PS. My Chase card reveals the credit card number, expiration date, and card holder name when read with a reader attached to my laptop.

  44. half year for a passport there? LMFAO.. here 30 Euro and in 3 hours done if yoou need fast, if not next day :))think we left US behind on this already…

  45. In response to the idea of tracking someone who has their cellphone turned off. Law enforcement already has this ability. I have a acquaintance who has worked with the U.S. Marshal’s Fugitive Task force. They are able to turn cell phones on remotely without there being any external signs that the phone is on. He said that the most difficult people to track are the ones who constantly dispose of, and purchase new track phones. But in the end, they all call their girlfriend/boyfriends and that tends to be a common downfall.

  46. I am reading brilliant ideas here but only solution is microwave which fries the chip forever.
    If you want to keep the magnetic stripe intact fold an aluminum foil and cover the stripe entirely by taping it (front and back). Make sure the tape seals the stripe entirely %100. Put a full glass of water in microwave and place the card right next to it. Zap it for 5 secs. You are all set.. you have a good old fashion credit card now;)

  47. how do you fry a an implanted under the skin chip? i was hoping this would be covered.
    i would hate to dig it out, that would leave evidence of tampering.
    charles kafka

    1. Charles Kafka, I recommend you break (or just bruise) (or report a suspected break or bruise on) whatever bone is beneath the chip. Then go get an x-ray. I hurt my arm one time and the guy did at least 2 x-rays on it to get different views.

      I don’t know, will x-rays disrupt RFID chips? I’m not a techie. Someone else, perhaps?

  48. I do not like them nor the system they are linked into and when people that rely on them entirely require (require=demand) that I have one in my hand, forehead or body just to buy or sell anything, I absolutely will not get one. I am free and to take one will mean that I am giving that freedom over to someone else. I would rather go hungry than to take one. I would rather cut them off of my clothes and remove them from the products I buy, dumping them into the store’s trash cans, than to have them hanging around in my home for some company to know where their merchandise went and who is with it simply because they are able to utilize GPS, etc. E-gad. It almost seems like they are attached to all of ‘their’ things and they want to make sure they are alright. I wonder if there is a world that I can go to where nosy merchandisers and other people do not live so I will never have to think about whether or not they are trying to pry into my life anymore. All in the pursuit of happiness (financial happiness).

  49. I’m glad I found this before buying. What about using the HVAC aluminum duct tape? Post office priority mail (or UPS / FEDEX) envelopes are available made from tyvek. Put the two together to make your own sleeve. The duct tape can be pricy so ask a local HVAC contractor if you might borrow some. I already have it from other projects. Too bad I can’t just tape it to the cover of the passport.

    Would the silver bubble wrap used for insulation work too?

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