4 ms·

Replication Prohibited: Attacking Restricted Keyways with 3D Printing [pdf]

75 points by 1970-01-01 3y ago

Animats 3y ago
This must be an old paper. No visible date. (Put a date in your PDF file, please. The papers are not being delivered bound into a magazine or proceedings any more.) People have been 3D printing keys for years.[1][2] Most of that is overkill. If it's just a pin-tumbler lock, simple picking techniques will usually work. [1] https://www.youtube.com/watch?v=cexGEYxoMe0 https://www.youtube.com/watch?v=cexGEYxoMe0 [2] https://www.instructables.com/How-to-make-a-3D-printed-keyFULL-TUTORIAL https://www.instructables.com/How-to-make-a-3D-printed-keyFU...
- NoZebra120vClip 3y ago
  That's what metadata is for! Created and modified: 7/21/15. "woot15" in the pathname may also be a clue for us: https://www.usenix.org/conference/woot15 https://www.usenix.org/conference/woot15 tptacek is listed as co-chair and committee member. Hi there!
  - JohnFen 3y ago
    Metadata is often stripped out or mangled, though, so including the date in the document itself is still a useful thing to do.
- darksim905 3y ago
  having the key and/or at least the ability to quickly make a key is far quicker than picking and much better if you are intending on being surreptitious. It also aids in less forensic evidence behind.
feb 3y ago
The paper explains how to get the profile of the key to 3D print the equivalent of key blanks. But one needs the cuts in the key and that part is secret that cannot be easily detected from a photo of the key hole.
- rini17 3y ago
  It also explains that having a key blank allows for attacks such as bumping. Also cuts can be easily reconstructed from photo of the keys.
- michaelt 3y ago
  Restricted keyways try to protect against the following threats: * Unauthorised key duplication. Think of a college dorm where residents all have keys, but you don't want them making copies, and keeping access to the dorm after they move out. So they use a design that most locksmiths don't have key blanks for. * Basic keyholders getting masterkeys by taking locks apart. Think of a college dorm where they want every resident to be able to open the front door, but not each others' dorm rooms, and they want the fire department to have one key that will work for all the rooms. Because of the way masterkey systems work, a resident can take the lock off their dorm room door, measure some internal components, and figure out the cuts on the fire department master key. Restricted key blanks make this a lot harder. Of course, this doesn't provide perfect security. Restricted keyways don't protect against someone with a CNC milling machine, or someone with a set of files and a lot of patience, or someone willing to break a window. Modern buildings rarely install new masterkey systems these days - electronic locks are a much better system.
  - samstave 3y ago
    Here is a video I made some years ago picking locks for Handguns... with a spinning keyway useless cover... You can see that some manufacturers obviously take these items as a joke and its weird that something like these keyway spinner things subconsciously add a tiny thought of more security - when it may as well have been made of paper mache. https://www.youtube.com/watch?v=u3I6lbpF68Q https://www.youtube.com/watch?v=u3I6lbpF68Q https://www.youtube.com/watch?v=u3I6lbpF68Q https://www.youtube.com/watch?v=u3I6lbpF68Q Would love to get /u/LockPickingLawyer's opinion on this article.
    - aidenn0 3y ago
      Gun locks are notoriously easy to pick. I think the threat model for them is "A toddler found your gun" more than anything else.
opengears 3y ago
Nice username :D
kitd 3y ago
Semi-related: I have been reading Ben Macintyre's history of Colditz, the WW2 POW camp. The prisoners used to intercept incoming packages that contained secret information and tools used for escaping, to remove it before the packages were inspected by the guards. The guards suspected this and enhanced the locks on the mail room. One of the prisoners was a notorious French cat burglar who prided himself in being able to pick any lock. Sure enough, every time the locks were enhanced, he'd learnt how to unlock them within about a week. Some of the details were amazing. The locks were quite advanced, using a four-way set of teeth, each tooth angled in 2D to micrometer precision. And yet, using quite rudimentary tools (often sneaked in in previous packages), he was able to reconstruct keys "borrowed" from unknowing guards. I found it quite amusing, especially as the guards often assumed their security was unbreakable. Heard that one before, lol ...
- linsomniac 3y ago
  Not sure if I read that book or another one, but I don't recall discussion about the mail room so probably a different one. Colditz is a great story, highly recommended reading. Also recommend Between Silk and Cyanide.
- JohnFen 3y ago
  > especially as the guards often assumed their security was unbreakable It's surprising how often people forget (or never learned) the guideline that thinking a thing is "secure" is itself a security vulnerability.
- gpderetta 3y ago
  Guarding the mail-room 24/7 was not an option?
kickofline 3y ago
(2015)
fargle 3y ago
This is very interesting. I'm wondering why not print the blanks with a gap at the bottom so there's room to insert a lock-pick tension wrench to apply the torque instead of using the keyhead. That way the torque capacity of the plastic is basically irrelevant, just print with the best quality and/or cheapest material.

75 points by 1970-01-01 3y ago

This must be an old paper. No visible date. (Put a date in your PDF file, please. The papers are not being delivered bound into a magazine or proceedings any more.) People have been 3D printing keys for years.[1][2] Most of that is overkill. If it's just a pin-tumbler lock, simple picking techniques will usually work. [1] https://www.youtube.com/watch?v=cexGEYxoMe0 https://www.youtube.com/watch?v=cexGEYxoMe0 [2] https://www.instructables.com/How-to-make-a-3D-printed-keyFULL-TUTORIAL https://www.instructables.com/How-to-make-a-3D-printed-keyFU...

NoZebra120vClip 3y ago
That's what metadata is for! Created and modified: 7/21/15. "woot15" in the pathname may also be a clue for us: https://www.usenix.org/conference/woot15 https://www.usenix.org/conference/woot15 tptacek is listed as co-chair and committee member. Hi there!
- JohnFen 3y ago
  Metadata is often stripped out or mangled, though, so including the date in the document itself is still a useful thing to do.
darksim905 3y ago
having the key and/or at least the ability to quickly make a key is far quicker than picking and much better if you are intending on being surreptitious. It also aids in less forensic evidence behind.

feb 3y ago

The paper explains how to get the profile of the key to 3D print the equivalent of key blanks. But one needs the cuts in the key and that part is secret that cannot be easily detected from a photo of the key hole.

rini17 3y ago
It also explains that having a key blank allows for attacks such as bumping. Also cuts can be easily reconstructed from photo of the keys.
michaelt 3y ago
Restricted keyways try to protect against the following threats: * Unauthorised key duplication. Think of a college dorm where residents all have keys, but you don't want them making copies, and keeping access to the dorm after they move out. So they use a design that most locksmiths don't have key blanks for. * Basic keyholders getting masterkeys by taking locks apart. Think of a college dorm where they want every resident to be able to open the front door, but not each others' dorm rooms, and they want the fire department to have one key that will work for all the rooms. Because of the way masterkey systems work, a resident can take the lock off their dorm room door, measure some internal components, and figure out the cuts on the fire department master key. Restricted key blanks make this a lot harder. Of course, this doesn't provide perfect security. Restricted keyways don't protect against someone with a CNC milling machine, or someone with a set of files and a lot of patience, or someone willing to break a window. Modern buildings rarely install new masterkey systems these days - electronic locks are a much better system.
- samstave 3y ago
  Here is a video I made some years ago picking locks for Handguns... with a spinning keyway useless cover... You can see that some manufacturers obviously take these items as a joke and its weird that something like these keyway spinner things subconsciously add a tiny thought of more security - when it may as well have been made of paper mache. https://www.youtube.com/watch?v=u3I6lbpF68Q https://www.youtube.com/watch?v=u3I6lbpF68Q https://www.youtube.com/watch?v=u3I6lbpF68Q https://www.youtube.com/watch?v=u3I6lbpF68Q Would love to get /u/LockPickingLawyer's opinion on this article.
  - aidenn0 3y ago
    Gun locks are notoriously easy to pick. I think the threat model for them is "A toddler found your gun" more than anything else.

opengears 3y ago

Nice username :D

kitd 3y ago

Semi-related: I have been reading Ben Macintyre's history of Colditz, the WW2 POW camp. The prisoners used to intercept incoming packages that contained secret information and tools used for escaping, to remove it before the packages were inspected by the guards. The guards suspected this and enhanced the locks on the mail room. One of the prisoners was a notorious French cat burglar who prided himself in being able to pick any lock. Sure enough, every time the locks were enhanced, he'd learnt how to unlock them within about a week. Some of the details were amazing. The locks were quite advanced, using a four-way set of teeth, each tooth angled in 2D to micrometer precision. And yet, using quite rudimentary tools (often sneaked in in previous packages), he was able to reconstruct keys "borrowed" from unknowing guards. I found it quite amusing, especially as the guards often assumed their security was unbreakable. Heard that one before, lol ...

linsomniac 3y ago
Not sure if I read that book or another one, but I don't recall discussion about the mail room so probably a different one. Colditz is a great story, highly recommended reading. Also recommend Between Silk and Cyanide.
JohnFen 3y ago
> especially as the guards often assumed their security was unbreakable It's surprising how often people forget (or never learned) the guideline that thinking a thing is "secure" is itself a security vulnerability.
gpderetta 3y ago
Guarding the mail-room 24/7 was not an option?

kickofline 3y ago

(2015)

fargle 3y ago

This is very interesting. I'm wondering why not print the blanks with a gap at the bottom so there's room to insert a lock-pick tension wrench to apply the torque instead of using the keyhead. That way the torque capacity of the plastic is basically irrelevant, just print with the best quality and/or cheapest material.