
Cracking Bitcoins private keys generated from weak passphrases - jwmoraes
https://github.com/joarleymoraes/lousy_bitcoins
======
blakdawg
FYI, [https://github.com/dan-v/bruteforce-bitcoin-
brainwallet](https://github.com/dan-v/bruteforce-bitcoin-brainwallet)

------
paulpauper
before you get too excited, someone tried this a year or so ago. grand total:
.002 bitcoins (some really small amount)

~~~
blakdawg
Earlier attempts were more successful: (PDF)
[http://fc16.ifca.ai/preproceedings/36_Vasek.pdf](http://fc16.ifca.ai/preproceedings/36_Vasek.pdf)

"Abstract. In the cryptocurrency Bitcoin, users can deterministically derive
the private keys used for transmitting money from a password. Such "brain
wallets" are appealing because they free users from storing their private keys
on untrusted computers. Unfortunately, they also enable attackers to conduct
unlimited online password guessing. In this paper, we report on the fi rst
large-scale measurement of the use of brain wallets in Bitcoin. Using a wide
range of word lists, we evaluated around 300 billion passwords. Surprisingly,
after excluding activities by researchers, we identi ed just 884 brain wallets
worth around $100K in use from September 2011 to August 2015. We fi nd that
all but 21 wallets were drained, usually within 24 hours but often within
minutes. We fi nd that around a dozen "drainers" are competing to liquidate
brain wallets as soon as they are funded. We fi nd no evidence that users of
brain wallets loaded with more bitcoin select stronger passwords, but we do
find that brain wallets with weaker passwords are cracked more quickly."

