StarkWare Mines Bitcoin’s First Quantum-Safe Transaction on Mainnet

• StarkWare announced Wednesday that a transaction using its Quantum Safe Bitcoin (QSB) method was confirmed in block 964,199, mined by MARA Pool at 8:48 p.m. UTC.
• QSB, designed by StarkWare researcher Avihu Levy, uses “signature grinding” to rest security on hash functions instead of the elliptic-curve cryptography a quantum computer could break.
• StarkWare says QSB does not make Bitcoin itself quantum-safe, and CEO Eli Ben-Sasson still wants and expects a protocol-level soft fork.

StarkWare says it has run the first quantum-safe Bitcoin (BTC) transaction on mainnet, a spend confirmed in block 964,199 on Wednesday that is designed to shield the moved coins from future quantum attacks without changing Bitcoin’s consensus rules.

Chain data from Mempool.space shows the transaction combined inputs of 39,179 and 10,000 satoshis into a single 44,000-satoshi output, paid 5,179 satoshis in fees and was mined by MARA Pool at 8:48 p.m. UTC on Aug. 26. 

QSB transactions use a nonstandard format that ordinary nodes will not relay, so StarkWare submitted the spend directly to the miner through MARA’s Slipstream service.

Grinding for a Valid Signature

The method, called Quantum Safe Bitcoin, was designed by Avihu Levy, researcher and general manager of applications at StarkWare, who published the technique and an open-source repository in April.