3 ms·

Yea -- the common rectangle ones with 10 buttons don't care about ordering, so you have combinations not permutations, and a tiny search space.

• mikeash 12y ago
  Just to put a number on "tiny": if there are 10 buttons and the code is 5 digits long, there are 252 possible combinations. If it takes you four seconds to try a combination then your expected time to brute force the code would be about 8 minutes.
  • nostromo 12y ago
    This isn't a concern on newer locks. You can use longer codes, order matters, and they throttle failed passcode attempts to prevent brute-force attacks.
    • mikeash 12y ago
      I assume you mean electronic locks? Simple mechanical code locks are still pretty common.