btclib: a python library for 'bitcoin cryptography'
btclib is a python3 type annotated library intended for teaching and demonstration of the elliptic curve cryptography used in bitcoin.
It does not have external requirements or dependencies; to install (and upgrade) it:
python -m pip install --upgrade btclib
Originally developed for the Bitcoin and Blockchain Technology course at Milano Bicocca and Politecnico di Milano, its algorithms are not intended for production environments: they could be broken using side-channel attacks; moreover, they are often refactored without care for backward compatibility.
The library includes:
- modulo algebra functions (gcd, inverse, legendre symbol, square root)
- octets / integer / point conversion functions
- elliptic curve class
- fast algebra implemented using Jacobian coordinates
- double scalar multiplication (Straus's algorithm, also known as Shamir's trick)
- multi scalar multiplication (Bos-coster's algorithm)
- point simmetry solution: odd/even, low/high, and quadratic residue
- available curves: SEC 1 v1 and v2, NIST, Brainpool, and low cardinality test curves
- DSA signature with (transaction) DER encoding and (message) compact encoding
- Schnorr signature (according to
- batch validation
- threshold signature (see test-suite)
- MuSig multi-signature (see test-suite)
- Borromean ring signature
- RFC 6979 to make signature schemes deterministic
- Sign-to-contract commitment
- Pedersen Committment
- Base58 encoding, addresses, WIFs
- BIP32 hierarchical deterministic wallets
- BIP39 wordlists and mnemonic for generating deterministic keys
- Electrum standard for mnemonic
A very extensive test suite reproduces results from major official sources and covers 100% of the library code base.