gionasoldati / bitcoinblockchaintechnology

Python library and Excel spreadsheets for the Bitcoin & Blockchain Technology course

btclib: a bitcoin cryptography library

http://github.com/dginst/btclib

btclib is a python3 type annotated library intended for teaching and demonstration of the cryptography used in bitcoin. It is used for the Bitcoin and Blockchain Technology Course at Milano Bicocca and Politecnico di Milano.

To install (and upgrade) btclib:

python3 -m pip install --upgrade btclib

Algorithms are not to be used in production environments: they could be broken using side-channel attacks. Moreover, they might be subjected to major refactoring without care for backward compatibility.

The library includes:

• modulo algebra functions (gcd, inverse, legendre symbol, square root)
• octet / integer / point conversion functions
• elliptic curve class
  • fast algebra implemented using Jacobian coordinates
  • double scalar multiplication (Shamir's trick)
  • point simmetry solution: odd/even, high/low, and quadratic residue
  • SEC 1 v1 and v2 curves
  • NIST curves
  • low cardinality test curves
• ECDSA signature and DER encoding
• Sign-to-contract notarization
• Schnorr signature (according to bip-schnorr bitcoin standardization)
  • batch validation
  • threshold signature
  • MuSig multi-signature
• Borromean ring signature
• RFC-6979 to make signature schemes deterministic
• EC Diffie-Hellman
• Pedersen Committment
• base58 encoding, addresses, WIFs
• BIP32 hierarchical deterministic wallets
• BIP39 mnemonic code for generating deterministic keys
• Electrum standard for mnemonic code

A very extensive test suite reproduces results from major official sources and covers basically 100% of the library code base.