2 ms·
To counteract brute-forcing, how about adding a rate-limiting mechanism? I could imagine each attempt to rotate the cylinder could partially compress a spring-
by HellsMaddy 4y ago
To counteract brute-forcing, how about adding a rate-limiting mechanism?
I could imagine each attempt to rotate the cylinder could partially compress a spring-loaded lever. There could be some sort of ratcheting return mechanism that allows the spring to decompress at a known rate (think a kitchen timer). Once the spring is compressed beyond a certain point (e.g. after 5 failed attempts), a mechanism locks out the cylinder until the return mechanism allows the spring to decompress back to its starting position.
If the lockout happened after 5 failed attempts, and the lockout duration was 10 minutes, an attacker could test at a maximum rate of 30 combinations per hour. It would take 64 days to check all 46,656 possible combinations, or 32 days on average to find the solution.
- lexicality 4y agoSounds like an interesting way to get locked out of your house. You would need successful uses of the key to reset the ratchet or every 5 times you opened your door it would become inoperable for 10 minutes, assuming the spring for the timer hasn't rusted or got a bit of grit in it or whatever.
- HellsMaddy 4y agoRevised: - Each [failed] attempt to rotate the cylinder could partially compress a spring-loaded lever. - The return mechanism would always return if not in its resting position, not only after each 5 failures. - Successful attempts immediately reset the spring.