I got a lot of great feedback and questions after posting my article about brute forcing yesterday

I wanted to address a question that came up over and over again because I think a lot of people extrapolated what I did to the false conclusion that Bitcoin isn't safe or secure /0

Q: Are my bitcoins stored in a wallet generated from a 12-word mnemonic safe?
A: Yes, just don't give out any of your words on Twitter.

Brute forcing @alistairmilne's wallet was only possible because he publicly exposed eight words from his twelve word mnemonic seed. /1

It would take the same system that brute forced the last 4 words of his mnemonic 837 quintillion millennium to brute force all possible 12 word mnemonics. /2

Sure, there are still lots of ways to optimize the system but even a 10x improvement in performance would be surprising to me at this point. /3

And yes, you could increase spending to rent more computing power or even develop an ASIC but the amount of money you would 'reasonably' spend is capped at ~$100B (BTC market capitalization) /4

Assuming you could actually spend $100B on GPUs you would still 'only' be getting 200,000,000x performance improvement.

So 200,000,000x increase in spend and 10x performance optimization gets you ~2 billion times total increase in brute forcing capacity. /5

Great, now you can brute force mnemonics in 1 day if you know as few as 5 words.

To brute force all 12 words (just to break even on your $100B investment, assuming you can actually liquidate all the BTC) still takes 422 TRILLION YEARS. /6

Your bitcoin is safe. 2^128 is a REALLY big number. Just don't let anyone near your seed words. /fin