Quantum-safe Bitcoin transactions get 79% cheaper to build

What happened

StarkWare reported on 23 September 2026 that the Quantum-Safe Bitcoin Optimization Challenge, opened with Yukon Research and Eigen Labs after the first quantum-safe transaction was mined in August, cut the GPU compute needed to build one such transaction by 79% in a week: from roughly 3,100 GPU-hours, about $320, for the mainnet transaction to an estimated $67. The estimate comes from the challenge's benchmark, which reproduces the GPU grinding work and builds no transactions itself. The two leaderboard records were held by developers running the AI models Opus 5 and Fable 5.1. StarkWare still considers a soft fork the better long-term answer for broad quantum protection on Bitcoin.