QSBitcoin: A quantum-safe implementation of Bitcoin Core protecting your assets against future quantum threats

Status: QSBitcoin is a work-in-progress quantum-safe Bitcoin implementation based on Bitcoin Core v28.0. It adds NIST-standardized post-quantum signatures while maintaining full backward compatibility with the Bitcoin network. Currently active on testnet and regtest networks for testing and development.

🚧 Work in Progress: QSBitcoin's quantum-safe features are actively being developed and tested on testnet/regtest networks.

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QSBitcoin uses peer-to-peer technology to operate with no central authority or banks; managing transactions and the issuing of qsbitcoins is carried out collectively by the network. QSBitcoin is open-source; its design is public, nobody owns or controls QSBitcoin and everyone can take part.

Quantum-Safe Technology

NIST-Standardized Algorithms

QSBitcoin implements two NIST-standardized post-quantum signature schemes: ML-DSA-65 (Module-Lattice Digital Signature Algorithm) for standard transactions and SLH-DSA-192f (Stateless Hash-Based Digital Signature Algorithm) for high-value cold storage.

Unified Opcodes

Using innovative unified opcodes (OP_CHECKSIG_EX and OP_CHECKSIGVERIFY_EX), QSBitcoin supports multiple quantum algorithms with just two new opcodes, reducing complexity and improving extensibility.

Soft Fork Activation

QSBitcoin is implemented as a soft fork of Bitcoin Core, meaning it's fully backward compatible. Both ECDSA and quantum signatures are accepted, allowing users to migrate at their own pace.

Latest Development Updates

🔄 July 2025: Fee Structure Simplified

Removed dynamic fee calculations to align more closely with original Bitcoin. Fees are now based purely on transaction size, making the implementation simpler and more Bitcoin-compatible.

🔧 Critical Bug Fixes Completed

Fixed quantum signature verification, manual UTXO selection, and witness script parsing. All quantum addresses can now generate, receive, and spend funds successfully.

🚀 Active on Testnet/Regtest

QSBitcoin is fully operational on regtest and testnet networks. Both ML-DSA and SLH-DSA signatures work in all transaction scenarios. Mainnet activation awaits community consensus.

View on GitHub Implementation Status

Why Choose QSBitcoin?

Actively Developed

QSBitcoin is under active development as a quantum-safe Bitcoin implementation with comprehensive test coverage. Core features are operational on regtest and testnet networks.

Standard Fee Structure

QSBitcoin uses Bitcoin's standard fee structure based purely on transaction size. Quantum signatures require more space (ML-DSA ~3.3KB, SLH-DSA ~35KB) compared to ECDSA (~71 bytes), resulting in proportionally higher fees.

Flexible Migration

No forced migration - users control when to switch from ECDSA to quantum signatures. Mixed transactions supporting both signature types are fully supported.

Open Source & MIT Licensed

The complete implementation is available at github.com/qsbitcoin/qsbitcoin under the MIT license. Based on Bitcoin Core v28.0 with full documentation and test coverage.