bitstein/shamir39

Shamir's Secret Sharing for BIP39 passphrases

Shamir39

This library uses Trezor's BIP39 python-mnemonic and SLIP39 python-shamir-mnemonic libraries to perform Shamir's Secret Sharing on a BIP39 passphrase.

⚠️ This is untested software based on software that remains under review. Use at your own risk, and don't use it to protect money! ⚠️

Usage

This software is written in python3 and should not rely on third-party libraries. Trezor libraries are included. Please ensure they are up to date before using.

usage: shamir39.py [-h] (-c | -s) -t THRESHOLD [-n NUMBER]

optional arguments:
  -h, --help            show this help message and exit
  -c, --combine         Recover secret from shares
  -s, --split           Split secret into shares
  -t THRESHOLD, --threshold THRESHOLD
                        Number of shares required to recover secret
  -n NUMBER, --number NUMBER
                        Number of total shares

Learn More

• BIP39: Mnemonic code for generating deterministic keys: https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
• SLIP-0039 : Shamir's Secret-Sharing for Mnemonic Codes: https://github.com/satoshilabs/slips/blob/master/slip-0039.md

Other Implementations

• Ian Coleman's slip39: https://github.com/iancoleman/slip39
• Unchained Capital's hermit: https://github.com/unchained-capital/hermit

Criticism of Shamir's Secret Sharing

• "Shamir Secret Snakeoil" by Greg Maxwell [Bitcoin Wiki]
• "Shamir's Secret Sharing Shortcomings" by Jameson Lopp