Quote from: o_e_l_e_o on December 20, 2021, 09:36:10 PM

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.

Quote from: pooya87 on Today at 05:15:41 AM

To be clear the "good hardware" in this context for this duration means a 48-core cloud computing server not a regular good hardware PC. With a PC with the best CPU you would get a couple of hours, possibly 5 or 6.
That's for BIP39 mnemonic, but for Electrum it should take a lot less by a factor of about 12.

Exactly. That's why I am not a big fan of providing exact data and saying "I will take 7 days". It will take 7 days on one specific computer, while on other it would take 6 days or 8 days. If Google or Amazon would like to use their datacenters and their hardware, maybe it would take 5 minutes.
The point it to understand how difficulty (time estimation) changes when we change length of seed - they say size does not matter, but we clearly see the longer the better Grin