4 ms·

Hashes are now 256 bits. In order to get a collision with probability 1% you need to produce about 4e37 hashes. For comparison, if you had a 5GHz computer that

Hashes are now 256 bits. In order to get a collision with probability 1% you need to produce about 4e37 hashes. For comparison, if you had a 5GHz computer that did a SHA-256 hash every cycle and gave 100 of these computers to every human on Earth, it'd take over 300 million years to produce 4e37 hashes.

ShinTakuya 6y ago
Yep, basically while it's entirely possible (as per Murphy's Law) that there'll be an accidental collision, the likelihood is close to zero. It's a fair risk to be taking.
fenomas 6y ago
> In order to get a collision with probability 1% you need to produce about 4e37 hashes Does "get a collision" here mean finding a particular collision with a known hash, or finding any collision between any two of the generated hashes?
- doomrobo 6y ago
  The latter. I used the formula from the Wikipedia page on the birthday attack: p ~= 1 - e^{-n^2/2H} where n is the number of items you've picked and H is the size of the universe
  - fenomas 6y ago
    I see, thanks!