# Difference between revisions of "Talk:BIP 0039"

(Created page with "Here is a simple implementation of my proposal to 'mine' for a seed: <pre> from electrum import mnemonic import ecdsa import time import hmac import hashlib PREFIX = "100" ...") |
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The first 4 or 12 bits of PREFIX encode the length of the metadata (0 to e, f00 to fff) | The first 4 or 12 bits of PREFIX encode the length of the metadata (0 to e, f00 to fff) | ||

− | The length of the metadata in bits is 4*(n+1) where n is the value that is encoded. | + | The length of the metadata in bits is 4*(n+1) where n is the value that is encoded in the first bits. |

The format of the metadata itself remains to be defined. | The format of the metadata itself remains to be defined. | ||

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* 2000 to 2fff | * 2000 to 2fff | ||

*etc. | *etc. | ||

+ | |||

+ | [[User:ThomasV|ThomasV]] ([[User talk:ThomasV|talk]]) 15:06, 26 October 2013 (GMT) |

## Latest revision as of 15:06, 26 October 2013

Here is a simple implementation of my proposal to 'mine' for a seed:

from electrum import mnemonic import ecdsa import time import hmac import hashlib PREFIX = "100" n = len(PREFIX) entropy = ecdsa.util.randrange( pow(2,160) ) nonce = 0 while True: ss = "%040x"%(entropy+nonce) s = hashlib.sha256(ss.decode('hex')).digest().encode('hex') words = mnemonic.mn_encode(s)[0:13] # 13 random words seed = ' '.join(words) I = hmac.new("Bitcoin mnemonic", seed, hashlib.sha512).digest().encode('hex') if I[0:n] == PREFIX: break nonce += 1 print seed print I

PREFIX contains metadata about the wallet version.

The first 4 or 12 bits of PREFIX encode the length of the metadata (0 to e, f00 to fff)

The length of the metadata in bits is 4*(n+1) where n is the value that is encoded in the first bits.

The format of the metadata itself remains to be defined.

The most compact way to use it is probably to allocate version numbers.

Examples:

- 00 to 0f : length = 4 bits. 16 possible version numbers
- 100 to 1ff : length = 8 bits. 256 possible version numbers. (00 is used for Electrum's wallet structure)
- 2000 to 2fff
- etc.