A bitcoin "brainwallet" is a secret passphrase you carry in the "wallet" of your brain.

The Bitcoin Brainwallet Private Key Calculator calculates the standard base58 encoded bitcoin private key from your "brainwallet" passphrase.

The private key is the most important bitcoin number. All other numbers can be derived from it.

This command uses 3 other functions - all 3 are defined on my user page:

1) brainwallet_exponent() - search for Bitcoin Brainwallet Exponent Calculator

2) brainwallet_checksum() - search for Bitcoin Brainwallet Exponent Calculator

3) b58encode() - search for Bitcoin Brainwallet Base58 Encoder

Do make sure you use really strong, unpredictable passphrases (30+ characters)!

http:brainwallet.org can be used to check the accuracy of this calculator.

by David Winterbottom (codeinthehole.com)

]]>A bitcoin "brainwallet" is a secret passphrase you carry in your brain.

The Bitcoin Brainwallet Exponent Calculator is the second of three functions needed to calculate a bitcoin PRIVATE key. Roughly, checksum is the first 8 hex digits of sha256(sha256(0x80+sha256(passphrase)))

Note that this is a bash function, which means you have to type its name to invoke it

by David Winterbottom (codeinthehole.com)

]]>A bitcoin "brainwallet" is a secret passphrase you carry in your brain.

The Bitcoin Brainwallet Exponent Calculator is one of three functions needed to calculate the bitcoin PRIVATE key. Roughly, the formula is exponent = sha256 (passphrase)

Note that this is a bash function, which means you have to type its name to invoke it.

You can check the accuracy of the results here http://brainwallet.org

by David Winterbottom (codeinthehole.com)

]]>by David Winterbottom (codeinthehole.com)

]]>/dev/urandom relies on operator input to set the random seed. By itself, this may not contain enough random bits to produce high entropy output, especially if the system was recently restarted. Therefore, key stretching through a hash reduces the risk of using low-entropy output as a security key.

by David Winterbottom (codeinthehole.com)

]]>/dev/urandom relies on operator input to set the random seed. By itself, this may not contain enough random bits to produce high entropy output, especially if the system was recently restarted. Therefore, key stretching through a hash reduces the risk of using low-entropy output as a security key.

by David Winterbottom (codeinthehole.com)

]]>Of course you will have to install Digest::SHA and perl before this will work :)

Maximum length is 43 for SHA256. If you need more, use SHA512 or the hexadecimal form: sha256_hex()

by David Winterbottom (codeinthehole.com)

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