This Lock is a Paperweight Challenge
44sThe setup of finding a locked lock in a free bin and turning it into a challenge immediately grabs attention with a relatable and intriguing premise.
βΆ Play ClipAI Summary
The video documents the process of cracking a mechanical combination lock found at a thrift store. The creator explains the lock's mechanism, the mathematical challenge of finding the correct sequence, and ultimately succeeds in opening it by trying all possible combinations.
Chapters
[00:01]
The Lock Discovery
The lock was found in the free bin at a thrift shop because it was permanently locked, making it a challenge rather than a paperweight.
[00:14]
Initial Assumption
The lock has only four inputs (up, down, left, right), and if the combination were four moves long, there would be only 256 permutations, making it seem easy to brute-force.
[00:28]
The Dark Reality
The lock can be reset to any combination length, up to an infinite number of moves, because it acts as a mechanical hash function with four internal wheels.
[01:12]
The State Space
Michael Huebler calculated that the lock has only 7,501 unique internal states, meaning the effective search space is limited to that number.
[01:27]
The Cracking Strategy
Using collision findings from Blank Registration, the creator tries all 7,501 possible states, starting with the factory code, and successfully opens the lock in under 5 minutes.
[02:05]
The Next Challenge
After resetting the lock, the creator plans to find the longest sequence of moves with no shorter equivalent, making the lock harder to open in the future.
The video demonstrates that even a seemingly simple mechanical lock can be cracked by understanding its internal state space, and it ends with a humorous commitment to making the lock more challenging for future use.
Mentioned in this Video
Study Flashcards (4)
How many unique internal states does the lock have?
easy
Click to reveal answer
How many unique internal states does the lock have?
easy
Click to reveal answer
7,501
01:12
What are the four inputs on the lock?
easy
Click to reveal answer
What are the four inputs on the lock?
easy
Click to reveal answer
Up, down, left, and right.
00:14
What is the maximum length of a combination on this lock?
medium
Click to reveal answer
What is the maximum length of a combination on this lock?
medium
Click to reveal answer
Infinite, as it can be set to any number of moves.
00:41
Who calculated the number of unique states?
easy
Click to reveal answer
Who calculated the number of unique states?
easy
Click to reveal answer
Michael Huebler.
01:12
π‘ Key Takeaways
π
State Space Calculation
Reveals the mathematical foundation that makes cracking feasible.
01:12
π§
Collision-Based Cracking
Demonstrates a practical application of hash collisions in a physical device.
01:27Full Transcript
[00:01] found it in the free bin at my local thrift shop because, well, it doesn't permanently locked, which means it's basically just a paperweight or as I like to call it, a challenge. I mean, how hard could it be? There are only
[00:14] how hard could it be? There are only four inputs, up, down, left, and right. That's it. If a combination is four moves long, there are only 256 permutations with repetitions. I can try all of those. This is basically a fidget
[00:28] toy with a prize at the end. But then I looked into a combination can be and that's when things got dark. They come with a default factory code that is four moves long. But once you buy it, you can reset the code to whatever you want, up
[00:41] to a maximum of an infinite number of moves. You can set the combination on this lock to be 127 motions long, 127 million if you wanted to because this lock is a mechanical hash function. It can take any input and
[00:58] turn it into a hash that works with its internal mechanism, which happens to be four little wheels. When you slide this button, those four wheels turn different slide the button in. Now, you can slide this button all day and those wheels
[01:12] limitation is how many unique states all four of those wheels can be in together and Michael Huebler calculated the answer. It's 7,501. So, that's all I have to do. Or is it? Blank Registration went even
[01:27] lock never changed it from its factory code, within 6 minutes I should be able to crack it because Blank Registration found collisions, single strings of input that produce internal states equivalent to the states produced by all
[01:40] already tried four codes and it's still locked, but I'm 10% of the way through. And now I'm 20, 30, 40, I'm halfway through, 60, 70, perding-a. It took me
[01:52] less than 5 minutes. Left, left, right, up. This is great because my family has been needing a lock and now that I've cracked this one, I can reset it to whatever I want. So, my next challenge is to find the longest sequence of moves
[02:05] on this lock that has no shorter equivalent because then opening it would be really annoying and honestly, that's what life is about. Finding challenges whose solutions can then be used to make your life challenging again.
