schiavinato-sharing 0.4.1

Human-executable secret sharing for BIP39 mnemonics using GF(2053)

schiavinato-sharing-py

Python library for Schiavinato Sharing

Human-executable secret sharing for BIP39 mnemonics using GF(2053).

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⚠️ Status: Work in Progress

This library is functional but experimental (v0.4.1).

It is not professionally audited. Do not use for real funds until you have done your own review and the project has undergone independent security review.

Current Status

• Core GF(2053) arithmetic, polynomial ops, Lagrange interpolation
• BIP39 mnemonic split/recover with row + global checksums
• v0.4.1 parity with JS: dual-path checksum validation, checksum polynomials, security utilities, configurable randomness, and mnemonic helpers
• Comprehensive test suite (62 tests) with cross-implementation vectors

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🎯 What is Schiavinato Sharing?

Schiavinato Sharing is a secret-sharing scheme specifically designed for BIP39 mnemonic phrases using basic arithmetic in GF(2053). Unlike other schemes, it can be performed entirely by hand with pencil and paper, making it ideal for:

• 🏦 Long-term inheritance planning
• 🔐 Disaster recovery scenarios
• 🌍 Situations where digital tools are unavailable or untrusted
• 👨‍👩‍👧‍👦 Family backup strategies

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📦 Installation

pip install schiavinato-sharing

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🚀 Quick Start

Splitting a Mnemonic

from schiavinato_sharing import split_mnemonic

mnemonic = 'abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about'
k = 2  # threshold
n = 3  # total shares

shares = split_mnemonic(mnemonic, k, n)
print(shares[0].share_number)
print(shares[0].word_shares[:3])
print(shares[0].checksum_shares)
print(shares[0].global_integrity_check_share)

Recovering a Mnemonic

from schiavinato_sharing import recover_mnemonic

result = recover_mnemonic(shares[:2], word_count=12, strict_validation=True)
if result.success:
    print(result.mnemonic)
else:
    print(result.errors)

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📚 Documentation

Specification

This library implements the Schiavinato Sharing specification:

🔗 Specification Repository

Key documents:

• Whitepaper (LaTeX source) – Complete mathematical description
• Test Vectors – Validation data
• Reference Implementation – HTML tool

Sister Implementation

The JavaScript library is the primary implementation for end users:

🔗 JavaScript Library

npm install @grifortis/schiavinato-sharing

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🧪 Development

Setup

# Clone the repository
git clone https://github.com/GRIFORTIS/schiavinato-sharing-py.git
cd schiavinato-sharing-py

# Create virtual environment
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install development dependencies
pip install -e ".[dev]"

# Run tests
pytest

# Type checking
mypy schiavinato_sharing

# Linting
ruff check .

# Formatting
black .

Project Structure

schiavinato-sharing-py/
├── schiavinato_sharing/
│   ├── __init__.py
│   ├── field.py              # GF(2053) field arithmetic
│   ├── polynomial.py         # Polynomial operations
│   ├── lagrange.py           # Lagrange interpolation
│   ├── split.py              # Mnemonic splitting
│   ├── recover.py            # Mnemonic recovery
│   ├── checksums.py          # Checksum generation/validation
│   ├── security.py           # Constant-time comparisons + best-effort wiping
│   ├── seed.py               # Mnemonic helpers + native BIP39 checksum validation
│   └── types.py              # Dataclasses and typed error shape
├── tests/
│   └── ...
├── pyproject.toml
└── README.md

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🤝 Contributing

We welcome contributions! This project is in early development, so there's plenty to do.

How to Help

• 🐍 Implement core functionality – Help write the library!
• 🧪 Write tests – Ensure correctness with comprehensive tests
• 📖 Documentation – Improve README, docstrings, examples
• 🔍 Review – Check for bugs, security issues, or improvements

Getting Started

1. Read the spec: Schiavinato Sharing Whitepaper (LaTeX source)
2. Check test vectors: TEST_VECTORS.md
3. Look at JS implementation: schiavinato-sharing-js for reference
4. Open an issue: Discuss your contribution before starting

See CONTRIBUTING.md for detailed guidelines.

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🔒 Security

Security Status: ⚠️ EXPERIMENTAL (Not Audited)

This library is experimental software that has NOT been professionally audited.

DO NOT USE FOR REAL FUNDS until:

• Professional security audit
• Extensive peer review
• v1.0.0 release

See SECURITY.md for reporting vulnerabilities.

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📄 License

MIT License – see file for details.

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🔗 Related Projects

• Specification – Whitepaper and reference implementation
• JavaScript Library – Primary npm library implementation
• GRIFORTIS – Organization homepage

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📬 Contact

• 📖 Documentation: Specification repo
• 🐛 Bug Reports: Open an issue
• 💬 Discussions: GitHub Discussions
• 📧 Email: [e-mail]

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🙏 Acknowledgments

This implementation is based on:

• Shamir, A. (1979). "How to Share a Secret"
• BIP39: Mnemonic code for generating deterministic keys
• The Schiavinato Sharing specification by Renato Schiavinato Lopez, creator of Schiavinato Sharing and founder of GRIFORTIS

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Made with ❤️ by GRIFORTIS

Empowering digital sovereignty through open-source tools.