4 ms·
A $2k computer can do billions of hashes a second. 2^30 You're off by about 20 orders of magnitude (the joy of binary exponents).
by user5994461 6y ago
A $2k computer can do billions of hashes a second. 2^30
You're off by about 20 orders of magnitude (the joy of binary exponents).
- contravariant 6y agoI'm confused, 2^14 = 16384 is slightly more than 4 orders of magnitude, where did you get 20 from?
- bscphil 6y agoAn "order of magnitude" has no precise numerical meaning, it depends on what base you're working in. If the log of the number in base b increases by 1, you've increased 1 order of magnitude with respect to that base. (I don't know why the parent said "20", my instinct is to say 14 orders of magnitude here.)
- deleted 6y ago[deleted]
- contravariant 6y agoI've usually heard it being used to describe powers of 10. I'd be willing to accept 14 orders of magnitude since we're talking about powers of 2, but I still can't figure out where they got 20 from. Hence my question.
- user5994461 6y agoOne billion is 14 orders. We're talking billionS, that's a fair bit more (pun intended).
- craftinator 6y agoMaybe they forgot that Windows calculator doesn't respect order of operations...
- henns 6y agoThanks for pointing out that I was off in my original estimate (a hasty web search showed the wrong cryptocurrency; almost nobody mines bitcoin on CPUs anymore :). From what I can see, a more realistic estimate for a single core on a desktop is in the 2^26 range. Keep in mind that the PBKDF2 defender is single-threaded by design, whereas the attacker is not. This still represents ~a half million x advantage for the attacker/$2k they spend. For $1m, they can guess passwords ~200 million times faster than you. If we assume memory is the limiting factor for argon2, then even if a specialized attacker can use it at scale for 1/20th the cost, a 20x advantage is much better for the defender than a 500,000x advantage.