A Keygen For The Real World


[Nirav] found that he rarely printed anything useful with his RepRap, so to shake things up, he decided he needed to work on a project that didn’t involve printing yet more RepRap parts.

The goal of his project was to create working replicas of house keys by simply using the code imprinted at the factory. He purchased a handful of used lock sets from eBay, then carefully measured the keys with a ruler and calipers to get the blank dimensions just right. After that was done, he looked around online and was eventually able to create an OpenSCAD model using a chart of pin depth specifications he located. By changing the last line in the model’s code he can print any coded key. For keys lacking a code, he can manually measure the height of each bit and print replicas that way as well. Once printed, he says that they keys are strong enough to turn most locks he has come across, including deadbolts.

This is undoubtedly a neat project in its own right, though we would be interested to see if someone could get it paired with a program like SNEAKEY to generate bit measurements by sight alone.

39 thoughts on “A Keygen For The Real World

  1. Wow, I’m surprised the RepRap has enough precision. I’ve only ever seen them in pictures but it never looks like they’re all that good.

    Also surprised the keys are strong enough.

    Very awesome.

  2. Could a locksmith duplicate the plastic key? And even if they can — would they? Could be an easy way to get around those ‘do not duplicate’ keys…though I guess @TheCreator’s method of cutting a new one with a dremel would work just as well for that…

    1. I went to one of those “keys made” places, and the gal asked, “Howcome it says “do not dupoicate?” but she pronounced “duplicate” like the noun. (doop-li-cut.) I said something like, “Oh, it’s OK, I own the place.” and she went right ahead. It’s just words, after all.

  3. No need to marvel at the “precision” the reprap can produce. It’s more that these keys are so sloppy than the reprap is amazingly precise.

    And ABS keys….. with torque? No thanks, I would rather not dig a broken one out of a lock.

  4. Meh…I can look at your car key while its on the bar, read the bite, walk out to my car, kachunk me a quick copy, and open your car… cant drive it without the chip, but whats yours is mine…

  5. @Urza9814
    Teeth on a key (usually) have 9 possibles heights. A locksmith can spot those teeth heights from a mile away and make a key with matching teeth. Whether or not he would actually do that for someone I’m not sure.

    1. I once had a GF who had a kid who locked his key in the car that his dad had given him. We called a locksmith, and my GF, her kid, and her kid’s friend and I all went out to watch this guy pick the lock. He poked around and poked around and poked around, then stood up, said, “This isn’t working,” and walked over to the other side of the car. He had the lock picked before any of us even bothered to walk over and watch him. Like, three seconds! And none of us got to see him do it. )-;

      Back on topic, I wouldn’t trust a plastic key. I even broke off a brass one once, but the notch nearest the handle end was cut to the deepest level, leaving a weak spot.

  6. What is PLA’s tensile strength vs ABS? No real desire to spend 5 minutes looking it up. This strikes me as more of a gimmick that works some of the time rather than a real solution. Now, laser sinter these or medicos in stainless or titanium and then you are on to something.

  7. What about instead of a picture, you use something like radar to get measurements of the key? You might (this is a stretch) be able to use the radar to see the internals of the lock itself and generate a key for that so you don’t need access to the key.

    These are all just thoughts. Nothing concrete in my idea.

  8. Seems like this project is getting a bit of a hard time. I doubt the idea is that the keys replace their metal counterparts full time. But as a handy cheap backup or a quick one-time key, it’s pretty cool.

    As someone said, you could use a torsion wrench if you’re that worried.

  9. It must be a glorious time to be a criminal. This sort of thing plus some social engineering and/or monitoring tools would make all kinds of grand heists more attainable.

  10. I’m more intrigued by how he’s using the factory code to generate keys. It makes sense now that the factory code is a serial code and would correlate to the unique key, but I never knew this before.

    Also, maybe it’s just me or how the focus is blurred on the original key or the angle it’s taken at, but the second and third pins looks slightly off. Still, kudos for this interesting hack.

  11. a lot of negative comments: Its a KEY! printed! Now wire the shopbot up so it can print my flying car. 2011 is here!

    nice job, and most locks dont need a lot of torque, just push/pull/lift the door a bit. if still worried use a tension wrench, this still works better (faster/less skill) than picking it.

  12. This is an amazing, creative use of reprap, showing how weak key security is, at least for these keys, opening up possibilities and all I read here is ‘meh’ and retarded comments.

    Kudos to the hacker.

  13. @MorganLeFay

    Shapelock (called Polymorph here in the Uk) is no good for making keys.

    Like the person in this blog, I was strugling of things to make and the only thing I came up with was duplicating a key.

    I used a blob of Polymorph to make a mould, and then a second blob to create the duplicate key.

    The tolerances were well out, even on a very, very basic key. I was using a scalpal to clean it up, but still no use.

    Also for the thickness of the key, the Polymorph material was too flimsy. I was working on buiding the key around a sewing needle to give it some strength but lost interest very quickly.

    Btw, I think the point of this hack has been missed a little. He is not just “cloning keys”. If you give him the serial number from a lock, he can print you off a new key. Even without the original.

    Very cool.

  14. Well I scoff at anyone who thinks any lock can keep their home secure! I haven’t seen many homes that can’t be ‘opened’ without a key in less than a minute or two. doors can be forced, windows opened…

    Locks are meant to keep honest people honest, nothing more.

    Alarms offer some piece of mind, but most of them aren’t that hard to get around if you know a little bit about how they are installed.

    Want to protect your property a shotgun and your presence is about the best way. Low light, bright light, no light, a little indiscriminate, but if your lurking in my house you won’t likely survive long.

    Creating a key from a serial number is a piece of cake too, that is done all the time.

    However, to this specific article I say great job. I have thought about building a reprap for a while now, but haven’t come up with many real world uses for one, so I haven’t done it. Being able to print a key for emergency use GREAT. To those who say plastic keys are stupid, I know a few years back you could by plastic keys (Auto and home) that were cut out of a credit card sized piece of plastic and fit neatly into your wallet. Will they stand up to daily use, probably not, but in an emergency, or to have another key made, sure works great, go through metal detectors too, so travel is easier. Though they would probably be considered a weapon.

  15. Hundred-dollar locks and special keys…state of the art alarms… shotguns… big dogs…
    Why? who whould want to steal your Star Wars collection?
    Just kidding. Nice project, out of the box thinking :)

  16. >Locks are meant to keep honest people honest, nothing more.

    Locks are meant to throw up a physical and psychological barrier to thieves. Even if they are not perfect security (and what is?), they cost a bugler time and make him more conspicuous.

    I have a >$100 deadbolt on my front door even though I know that someone could get inside quickly with only a circular saw (2×4, siding, drywall and a bit of insulation). He’d be pretty conspicuous doing so, where he could probably open a KW1 lockset with a bumpkey quietly in about 30 seconds.

    Back this up with an alarm or dog, a cellphone, and a personal firearm.

    When seconds count, the police are only minutes away – youtube /watch?v=OkS8mdbml0A

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