Automatic lock cracker makes breaking and entering a breeze


For most people, forgetting the combination on a lock means breaking out the bolt cutters and chopping off the lock. Some students at the [Olin College of Engineering] decided there was a far more elegant way to do the job, so they built an automated lock-cracking machine.

The machine consists of a clamp to hold the lock, a solenoid to pull the lock open, and a stepper motor to run through the combinations. Most of the processing is done on the attached computer, using software they created. The application will brute-force all of the possible combinations if you request it, but it also allows you to enter the first, second, or third numbers of the combination if you happen to remember them.

Once the machine is started, the motor begins spinning the lock and the solenoid yanks on the latch until the combination is discovered, which takes a maximum of about two hours to complete. The opening of the latch trips a limit switch and causes the mechanism to stop. A simple button press then returns the lock’s combination to the user.

Be sure to check out the video embedded below of the lock cracker in action.

[via Wired]


  1. APerson says:

    2 much faster ways than 2 hrs of brute forcing. neat device the students here have cooked up and for some specialized application it may be useful, but it seems for the most part to be more rube goldberg than anything.

  2. goo says:
  3. CutThroughStuffGuy says:

    There are ways of deciphering master lock combos as well. Or just x-ray it.

  4. sanchezsucio says:

    Gee, it is a good thing no other manufacturers make combo locks or the Masterlock-specific hacks you mention would be rendered useless in certain situations.

    Oh wait…

    At least this machine can be altered to work on different locks.

  5. rageguy says:

    This video contains content from Sony Music Entertainment. It is not available in your country.


  6. chrome says:

    Fucking sony, I can’t watch the video in Belgium.

  7. Matthew says:

    “This video contains content from Sony Music Entertainment, who has blocked it in your country on copyright grouds.”

  8. Harry says:

    Fuck Sony!

  9. Matthew says:

    Hey, don’t blame Sony, blame the video authors who used material that isn’t theirs.

  10. c says:

    Mirror of video please.
    Also Fuck Sony!

  11. Kron says:

    fistfuck sony!
    everytime i see this message i just seed random sony music and backup another ps game

  12. fartface says:

    Hey students, we don’t care about your lame favorite song. STOP being “clever” and putting your lame as hell song in your video. All it does is cause problems to people.


  13. zitonguito says:

    view the video on youtube

  14. caleb says:

    *jumps on the bandwagon* fuck sony!

    also, 00 buck works great on those pesky combo locks :-D

  15. Stevie says:

    Yeah fuck Sony! Who the hell do they think they are protecting the copyright of their artists? I mean come on, wtf! Something that someone else makes should be free to me to get. If I spend years learning to do something (ie sing) and then making something which people love, then I want to get paid for it. But I aint paying shit for other peoples stuff.

  16. Stevie says:

    Btw for those bitching about Sony. You can actually watch it directly via the Youtube site

    Google make money from the ads and pay a minute amount to the copyright holder.

  17. Giant Enemy Crab says:

    Or you could get the locksmithing software, input the serial number on the back of the lock, press enter, bam there’s your combo.

  18. Oren Beck says:

    Neat Hack- and it’s 100% laid out to be a “non burglar” focused usage which keeps Hackerdom “White Hat” in the Reality of Perceptions. Points scored for that too. Their Alma Mater deserves creds for having such folks associated with them.

    Slagging the video and Sony? I pressed the youtube link and it just played for me in Kansas City, MO. Yes- it showed a stunning degree of Petty Bad about the copyfail handling. The video’s about the Hack more than whatever else experimental video wise- tried by the team stuff alongside the Hack.

    They’re gifted TECH folks. Expecting a MTV viddy is unfair. I’d be honored to work with these people any day! And- I’m showing their page to my 9 year old Granddaughter and 12 year old Grandson. Showing that women can do tech just as well-or better- than us old boys is a sky high multiplier for their team. I’d love to have them stop by CCCKC and give a presentation on how they did it. BtW- Poe’s on a few of my playlists:>

  19. c says:

    Nope same error!

  20. anonymus says:

    They could adapt this to crack combination lock safes. It would take a lot longer to run, but people may pay to have that old safe unlocked, rather than having to pay to have it taken away.

  21. BetaLyte says:

    Fucking Sony, with their stupid copyright bullshit.

    Thank you =)

  22. steaky says:

    some of us would actually make a shim out of a coke can and open it that way, sure you wont know the combination but its mush quicker

  23. hatemusic says:

    “This video contains content from Sony Music Entertainment, who has blocked it in your country on copyright grounds.”

    Who are Sony to also block THE VIDEO? Is it theirs also?

  24. signal7 says:

    meh. Unless this is used on a high security lock, it’s useless … and that’s not just true for Master locks – plenty of others have vulnerabilities that expose the potential numbers of the combination.

    Sure, you might have to run 50 or 100 combinations manually, but with some optimization, it does not take 2 hours to do so. I did it a couple of years ago in 30-45 minutes.

  25. CRJEEA says:

    I think you should make a lock cracker that listens for the click with I microphone and learns how to crack the lock combination. At first going through all possible combinations and monitering changes in the sound file. Then interperting when is the best time to change direction and check if the lock will open.

  26. moo says:

    Whats wrong with using a soda can and some scissors to open most cheap combo locks today?

  27. mic says:

    They don’t click at specific locations assuming they click at all. If they did they would be amusing puzzles for your kids, not locks.

  28. zool says:

    just use a shim

  29. Seshan says:

    This is why I use Dudly combo locks the masterlock combo locks are cheap POS

  30. aztraph says:

    I would love to see this in a portable version.

  31. namerequired says:

    @hatemusic: Funny thing is, it’s not Sony that’s blocking the video: It’s youtube. There’s absolutely nothing to stop them from showing that video without sound, but they decided that you and I need to be punished for these kids’ poor taste in generic hiphop background music.

    @zitonguito, @Stevie: The extent of censorship varies by country. From an IP Germany, you can’t see the video on the youtube site either.

    For those who can’t watch the video: Look at the picture. Imagine the text “This lock solution took 28 minutes” underneath the picture. Now imagine the solenoid jiggling the shackle of the lock very slightly around twice per second while the dial turns back and forth. Fast forward through a bunch more jiggling and turning. The lock opens. The End. You’re welcome :-)

  32. Trollicus says:

    I agree with Moo, I can open a master-lock like that in about 20 sec. I once got a summer job in High School removing old locks and cleaning out the lockers(among other tasks) With practice an a few bits I can open one faster without using the combination.
    I’m not knocking the build though, this would be great on the old safe I found in the book storage room(why did a HS need a safe anyway?) the safe was a real work of art though circa 1922 and big enough to hide a dead body(Dick Chaneys high school?) and I spent weeks before I finally got the thing open.

    Oh, BYT F*** Sony(sorry I’m still pissed at them for the root kit thing)

  33. Trollicus says:

    Just a thought, I wonder if Sony realizes it takes a lot of $$$ and effort to win over people with a commercial. With one Anti-commercial such as this Sony will need 1000 paid advertisements to compensate for the damage done. Sony might as well put a super bowl add that features Sony executives putting kittens in blenders and microwaves.

  34. -HMav says:

    I like seeing some of the hacks that come from the college kids with access to the fancy fab labs and such, but seriously, this hack has been done to death, and there is nothing special here. I think most would agree that this could be done in less than a few hours with an arduino and a junk r/c car, although the point stands that it is still cheaper and more time efficient to bypass the lock with a shim or simply cut it off and replace the lock. The weak point is almost never the locking mechanism itself, though I do think the exploits for different mechanisms are definitely hack worthy. This certainly is not. This is a purpose built machine designed to operate the lock as it was intended to be operated. Hackaday, I’ve been a long time reader, short time doer, but I have to say the content here is going down hill. Can we please get back to the original and creative hacks we all come here to see?

  35. Chuckt says:

    What do you do with safes that have more than three combinations? I have no idea how to open them.

  36. NatureTM says:

    damn, I’ve been thinking about doing this project for awhile. Nice job though.

  37. j-zero says:


  38. glen says:

    Sony Says no

  39. Max says:

    Dear Sony, every time you do this, a kitten gets it somewhere. Thankfully, sufficiently popular videos always end up mirrored or re-uploaded soon enough anyway. By all means, please do keep trying to move the ocean with a sieve, we like to watch you fail.

    Dear Youtube, surrendering the picture to a copyright claim of the soundtrack is downright moronic. I’m sure you guys are not that stupid, so you must be doing this on purpose to taunt us – which by the way doesn’t rhyme well with the “no evil” thingie. No matter, we still love you though.


  40. Sigg3 says:

    Hackaday’s new sponsor’s SONY ENTERTAINMENT.

  41. t&p says:

    We are not good enough to listen to the music so we are banned. What is the point to the music that they make if people can’t hear it. LOL @ copyrights. They protect “property” by not letting anyone see or hear it. Why not just not release it.

  42. Jessica says:

    A revised version of the video with no licensed music can be found at Enjoy international folks.

  43. Red says:

    May someone send me the diagram of this project please,or send me where i can find it…

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 96,704 other followers