Bitaddress.org is currently the most popular Bitcoin paper wallet generator. The code is open source, and no flaws have been found over the past few years.
Bitaddress gives you the option of auto generating private keys, using a ASCII character string to generate the key, or using what is know as a brain wallet, a group or combination of words and numbers that only you know.
Take a look at this wallet generated in 2015:
SHA256 private keys are almost impossible to hack, but the creator of that wallet made the mistake of using a brain wallet with the phrase:
As you can see, the funds were withdrawn immediately. We’re not sure if the owner withdrew them, or if they were stolen.
Either way, it is a good reminder that your brain wallet should not be a common phrase.
Stay tuned next week to find out how we cracked other brain wallets using a perl script.
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