StarkWare researcher Avihu Levy completed an experimental quantum-resistant transaction test on the Bitcoin mainnet, reportedly the first of its kind. The transaction was confirmed on Wednesday in Bitcoin block 964,199, spending an output of 10,000 satoshis protected by a Quantum Safe Bitcoin (QSB) scheme proposed by Levy, and was mined by MARA Pool through its Slipstream service.

The QSB scheme combines hash-based one-time signatures with computational search, aiming to prevent forgery even if quantum computers break the elliptic curve cryptography used by Bitcoin. StarkWare spokesperson Nathan Jeffay stated that the transaction cost approximately $150 to $200, and the computation took several hours. Since QSB transactions are classified as non-standard transactions under Bitcoin Core’s default relay policy, ordinary nodes do not propagate the transaction before confirmation, so it must be submitted directly through MARA’s Slipstream service.

QSB is only applicable to individual Bitcoin transactions and does not upgrade the cryptography of the entire network. StarkWare CEO Eli Ben-Sasson stated that a soft fork should occur, and QSB provides a safety net during the development of protocol-level protections. Additionally, Bitcoin developers are considering proposals like BIP-360, which would introduce a Pay-to-Merkle-Root output type while removing key path spends vulnerable to quantum attacks from Taproot.