4 ms·
It's an inevitable consequence of a good hash function. Every string you try is going to give you a different hash, so you just need to try enough strings. But
by plasticeagle 3y ago
It's an inevitable consequence of a good hash function. Every string you try is going to give you a different hash, so you just need to try enough strings.
But each time you add another digit to the prefix you're looking for, the difficulty of the match goes up by about 16 times.
If you're only looking for a few digits in the hash, then any brute force that is capable of changing the string every time you attempt the match will always find it. If you're looking for seven digits in the hash only, then it'll take on average 134217727 attempts. Which isn't really all that many on modern hardware.
- Obscurity4340 3y agoSo, implications-wise: where is the rub here? Where can this be used or exploited for fun or profit?
- rootw0rm 3y ago1.) Pick one of the old abandoned Bitcoin addresses 2.) Start looking for a key match using this technique 3.) Heat death of the universe 4.) Profit!
- Obscurity4340 3y agoI wonder how many of the Lastpass vaults had the private keys in the very unencrypted notes sections...
- Dylan16807 3y agoFind somewhere people look at only a small fraction of a hash? That's mostly git commits.
- rawling 3y agoOh, that's evil. In some places my tooling only shows 7 digits of the git SHA. I wonder how hard it would be to write something to tweak my commits until those are all the same. And I wonder how long it would take until someone noticed...