Key Takeaways Starkware’s QSB made a quantum-safe bitcoin transaction on Aug. 26 with zero consensus changes. Bitcoin gains an opt-in quantum hedge, but QSB cost $150-$200 and required hours of GPU work. Starkware still wants a Bitcoin soft fork after the QSB test; exposed keys remain a network risk. Starkware Shows Bitcoin Can Add Quantum Defense Without a Fork Bitcoin passed an unusual quantum-computing test: protecting a transaction without changing Bitcoin itself. On Aug. 26, a transaction using researcher Avihu Levy’s Quantum-Safe Bitcoin (QSB) construction was mined on the Bitcoin mainnet. Starkware described it as the first post-quantum-resistant bitcoin transaction …

