Re: How long to crack 24 word phrase if you know all 24 words out of order?
However, if you know the location of some of those words it would be easier (maybe possible) to brute force it. Because the difficulty increases exponentially
With good hardware, btcrecover will descramble a 12 word BIP39 seed phrase in an hour: https://btcrecover.readthedocs.io/en/latest/Usage_Examples/2020-05-02_Descrambling_a_12_word_seed/Example_Descrambling_a_12_word_seed/. Although not exactly the same due to the checksum, lets assume that if you know 12 out of the 24 words then you could descramble the remaining 12 words in roughly the same amount of time.If you don't know the position of 13 words instead of 12, then there are 13x as many combinations to try, so that would take roughly 13 hours.
For 14 words, 7 days.
For 15 words, 16 weeks.
For 16 words, 5 years.
For 17 words, 85 years.
For 18 words, 1500 years.
No point calculating beyond that really.
Not with quantum computers. I assume we won't need to wait 1500 years for the next generation computer to be developed.
Still, at current present technology levels we do not even need to talk about whether or not its possible to crack it because theoretically it is possible but its just technically impossible. Which to humans is almost exactly the same as literally impossible.
Also it bears reminding that by the time we have quantum computers powerful enough to do the entire cracking in minutes or hours or even days, at that point in the future we will have already upgraded the security where even quantum computers cannot crack it.
Its just a simple matter of adding more words.