keyphrase
A CLI utility that converts a private key expressed in hexadecimal to a phrase, with each word representing as close to 16 bits in your private key as your key's length allows. Also converts phrases back to their hexadecimal equivalents.
There are a few programs that do what this program does, but none I'd found that used a wordlist as extensive as I wanted. A more extensive wordlist allows larger keys to be encoded with fewer words. I wanted something that would give me a key I could reasonably memorize if I wanted to without compromising on security.
This program uses a 65,536 word list, allowing any private key to be encoded using as few English words as possible. For example, a 256 bit private key (such as the ones which underlie Bitcoin addresses) can be encoded using only 16 words without any loss of key strength.
WARNING: This is not a BIP-0039 implementation, and it does not contain the same safeguards as BIP-0039 does. There are words on the wordlist that differ by only a letter or two, and there is no checksum in the generated phrase. These were not features I particularly cared about and thus they were not features I included. If you want to make them options, though, I'd happily accept a pull request.
Compiling and Installing
make
make install
NOTE: On some systems, you may need to run sudo make install instead of just make install.
Usage
Creating a phrase from a private key:
$ keyphrase 0xFFFF562F8F9A961E158BDE2D4CCD2A64BB1D923208939714675BFAB28BBAF2A3
zyzzyvas flutings mushers octopuses bizones talkier evokers coagent ringer neutral antipode omnibus havening whistles mistitled vacuums
Getting a private key back from a phrase:
$ keyphrase "zyzzyvas flutings mushers octopuses bizones talkier evokers coagent ringer neutral antipode omnibus havening whistles mistitled vacuums"
0xFFFF562F8F9A961E158BDE2D4CCD2A64BB1D923208939714675BFAB28BBAF2A3
Bitcoin Examples
Getting a Bitcoin address and importable private key (WIF) from a 256-bit private key using pycoin (cross-platform):
$ python
>>> from pycoin.key import Key
>>> k = Key(secret_exponent=0xFFFF562F8F9A961E158BDE2D4CCD2A64BB1D923208939714675BFAB28BBAF2A3)
>>> print k.address()
1Cj9a8z4r7yoHcMB87LAd5dMJbeb4dFTYt
>>> print k.wif()
L5oLTsjGYwq8Suef1c5jDc6kLbYS6LG1VG7E1kFoN4hg2sVNoW3W
>>>
Getting a Bitcoin address and importable private key (WIF) from a 256-bit private key using bitcoin.sh (Linux-only):
$ source bitcoin.sh
$ newBitcoinKey 0xFFFF562F8F9A961E158BDE2D4CCD2A64BB1D923208939714675BFAB28BBAF2A3
---
secret exponent: 0xFFFF562F8F9A961E158BDE2D4CCD2A64BB1D923208939714675BFAB28BBAF2A3
public key:
X: CAFA2E819FFB11C209651801A47E574A330BDEEF805FB2689A1C2ADE3512F9B4
Y: 0AF853CFBECD031DBB5CAF3EE77CD35587D9CCA244B8F28910FC426E01C3E716
compressed:
WIF: L5oLTsjGYwq8Suef1c5jDc6kLbYS6LG1VG7E1kFoN4hg2sVNoW3W
bitcoin address: 1Cj9a8z4r7yoHcMB87LAd5dMJbeb4dFTYt
uncompressed:
WIF: 5Km2h5F7F312grYBstSzbaKyVTQSApQnsovX8saiKNEHzzX2psz
bitcoin address: 1Q7anhn5mgRHTivdujHeSVyRkeAtBmw8K7
$
Credit for bitcoin.sh goes to Lucien Grondilu's bitcoin-bash-tools.
Running Tests (with inotify-tools)
$ ./tests.sh --watch
Running Tests (without inotify-tools)
$ ./tests.sh
Notes
- Be very careful in transcribing your keyphrase if you choose to write it down somewhere. There are a lot of unusual words in this wordlist, and quite a few that are likely very similar to words you come across often in your day-to-day life. Make sure to try decoding your keyphrase back into your private key before destroying any copies of the original private key.
- If you're hacking on this project and you have inotify-tools installed, use the included test scripts! They'll give you the shiny, Grunt-like experience of having your tests compile and run automatically every time you make a change to your source files. If you're running Ubuntu, you can install the package with
sudo apt-get install inotify-tools. - Wordlist based on the English wordlist from SIL International.