Making A “Unpickable” Lock

Every time manufacturers bring a new “unpickable” lock to market, amateur and professional locksmiths descend on the new product to prove them wrong. [Shane] from [Stuff Made Here] decided to try his hand at designing and building an unpickable lock, and found that particular rabbit hole to be a lot deeper than expected. (Video, embedded below.)

Most common pin tumbler locks can be picked thanks to slightly loose fits of the pins and tiny manufacturing defects. By lifting or bumping the pins while putting tension on the cylinder the pins can be made to bind one by one at the shear line. Once all the pins are bound in the correct position, it can be unlocked.

[Shane]’s design aimed to prevent the pins from being set in unlocked position one by one, by locking the all pins in whatever position they are set and preventing further manipulation when the cylinder is turned to test the combination. In theory this should prevent the person doing the picking from knowing if any of the pins were in the correct position, forcing them to take the difficult and time-consuming approach of simply trying different combinations.

[Shane] is no stranger to challenging projects, and this one was no different. Many of the parts had to be remade multiple times, even with his well-equipped home machine shop. The mechanism that holds the pins in the set position when the cylinder is rotated was especially difficult to get working reliably.  He explicitly states that this lock is purely an educational exercise, and not commercially viable due to its mechanical complexity and difficult machining.

A local locksmith was unsuccessful in picking the lock with the standard techniques, but the real test is still to come. The name [LockPickingLawyer] has probably already come to mind for many readers. [Shane] has been in contact with him and will send him a lock to test after a few more refinements, and we look forward to seeing the results!

50 thoughts on “Making A “Unpickable” Lock

  1. Lift all the pins up, engage the “pin break”, turn the cylinder, disengage the pin break, let the pins fall in place. Depending on the machining tolerances, this should unlock it. It would be like a bump key, just not with the force of bumpkey, but the force of the pin springs. The pin break should be engaged by the rotation of the cylinder, not by the key, where the picker can control it.

  2. Any lock can be removed with a thermobaric lance. Even if you made it of stone.

    If I wanted something unsinkable, I’d use a key with no moving parts. An optical key and optical fiber lock, built out of AR 500, should be very penetration and pick proof.

      1. I meant no pins to move, only the unlocking bolt, not connected physically to the keyhole- a key and lock body that shines light through the key, tracking a specific time delay at specific angles through many channels of an optical fiber laced key with no geometry, like a cylinder filled with glass fibers.

        Kind of like the key to a Brama lock, but with no pins.

        Lock only opens when a specific time delay very precisely measured is achieved through optical feedback only.

        Something of that nature, only the bolt moves. No acceptable electronics- only pathways for optical fiber.

        Using a special glass for time delay of light, perhaps.

        Something like that was what I was thinking.

        1. I suspect there would be side channel attacks with something that intricate. I’d just use pure electronics. Take a smart card, put the reader in a faraday cage, and disconnect power and only use battery while doing crypto.

          I doubt anyone would get in unless they stole and reverse engineered the card, if it was competently made by security professionals.

          1. The main issue is availability of the locks. This comes down to cost, mostly. I have bought countless locks, brand new, and taken them apart. It took us months to get the Bowley single & double bitted locks. Beating them took only a few hours.
            The “Stealth key” lock is another one I would like to play with, but with the padlock costing $1000, I’ve only had a little hands-on time with no chance to pick it.

        1. Moderators can do anything. If they can’t they ask admin or programmer to make edits in db. That they don’t use such features (out of decency and good-will) is not evidence that they don’t exist. Also if your mail or data in some cloud is not e2e encrypted, owner of server definitely has access to them (but typically is not really interested in your files specifically).

        2. @Fosselius means going back to edit typos/thinkos/whatever in comments. It’s top on our list of features-to-add as well when we get some idle web-developer time.

          We’ve got some other fires that need putting out at the moment, though. Sigh.

          But I’m going to call it: 2021, Hackaday’s 17th anniversary, is going to be the year of editable comments. (I’ve been wrong about Linux on the desktop every year since 1994…)

  3. The purpose of a lock is to delay access, not prevent it. Most locks provide seconds of protection, if not less which is shocking to most. The best locks/doors will provide minutes of protection, which might be enough time to detect an intrusion is taking place and to do something about it. If you look at locks with that perspective, you’ll be way ahead of the game when it comes to home protection.

    1. You make a very good point. Locks, like laws, are only for the law-abiding. The guidelines “never pick a lock you depend on” and “never pick a lock for which you do not have permission” also bear repeating. Let not thy enthusiasm lead thou to the hoosegow.

      1. last i checked, $500,000 homes are still made with 2×4’s, drywall, plywood, and glass. nothing a [stolen] rock/sawzall/vehicle couldn’t break through for anyone dedicated to the cause.

          1. You say that, but I recall some guy in the VW community who had his garage broken into that way while he was away. They cut a hole through the wall big enough to crawl through.

            Not common, but still a valid approach.

    2. “The purpose of a lock is to delay access, not prevent it.” True, but sometimes that’s enough, thieves check multiple locked doors just to find one left unlocked, so the lock that is locked serves it’s purpose. A predator can eat a porcupine if it tries hard enough, but it’s easier to eat squirrels, so the porcupine isn’t eaten.

  4. I think it could still be picked, but you’d need a precise measurement gauge to tell you the rotation of the cylinder. Essentially, you’d try different positions for one pin at a time. When one pin is in the correct place, the amount of allowed rotation should be a tiny bit different. You might need to find out which is the first binding pin before you see a difference. You will also need a gauge to tell you what height you’re setting each pin to. As well, you’ll need a way to maintain the set of previously-done pins while testing the next pin. In other words, you’d need an adjustable key mechanism made for this specific lock. So, not impossible to pick, but very unlikely that anyone would have the right tools.

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