First Quantum-Resistant Bitcoin Transaction Confirmed on Mainnet Without Protocol Change

Reports indicate the first quantum-resistant Bitcoin transaction was confirmed on mainnet without any protocol change. The transaction used a post‑quantum signature scheme embedded in the transaction script/witness and was accepted and mined under existing consensus rules. This demonstrates that quantum‑resistant cryptography can be deployed on Bitcoin today via script‑level techniques rather than a soft fork, providing an incremental migration path. However, it does not retroactively protect existing keys and broader performance, interoperability, and standardization work is still required to address real-world quantum threats.