I never caught any big sharks like I thought, but now my wife runs a restaurant and occasionally employees just don't show up to work and leave things in their lockers. Once in a while it's clear it's to be annoying (locking supplies in their locker).
Never met a padlock or combination lock I couldn't shear through easily. Totally has paid for itself.
https://www.amazon.com/Lothee-Hydraulic-Cutting-Portable-Han...
And there are powered models too. The 3-foot snippers are long out of date for thieves.
The Louvre security staff similarly just learned this lesson.
The main thing locks do is make it noisy to get in.
A hardened metal safe designed to be resistant to cutting can still be cut through, just not in seconds with a screamer saw (trade name for a metal cutting circular saw)
If you want truly secure, encase your metal box in concrete like John Wick. Access is difficult but security is high :)
FYI, most safes already have a decently thick concrete layer — that’s most of why safes are heavy! (Or, I guess you could say, adding a concrete layer is cheaper than making the steel thicker.)
But they also have a rubber or foam (often styrofoam in cheaper safes) layer, to “smooth out” the force from a sledgehammer, jackhammer, or just dropping the thing out the window.
And a layer of compressible wet(!) sand, to spread out the point stress from a hammer and chisel, impact gun, gunshot, or small explosive configured for concussive force. (The goal here is essentially to replicate the behavior of a bulletproof vest.)
Plus, they often contain a layer to bind and foul and dull (or even break) the teeth of drill bits and reciprocating/chain/band saws. This can be any number of things — low-melting-point plastics, recycled broken glass, etc — but look up “proteus” for a fun read.
If the safe’s designer is clever, just a few materials can serve several of these functions at once. But more is always better. Which is why good safes (and vaults) are so dang thick. It’s not to solve one problem really well; it’s to mitigate N problems acceptably well, for a frighteningly large value of N.
In an analog to the somewhat frequent observation on HN that if you don't care whether the code is correct I can make it run arbitrarily quickly, if you don't care if the contents of the safe survive there's a lot of high-energy ways to blast it to smithereens. This is generally not considered a problem to be solved with a safe, though. If you want to prevent "being blasted to smithereens" that you'll need a completely different approach.
See https://www.youtube.com/channel/UCm9K6rby98W8JigLoZOh6FQ (LockPickingLawyer).
There went Uncanny X-Men 94 through 300.
Saw the same, except it was bolt cutters.
Most locks are only good if the attacker doesn't have any tools.