Quantum-Safe Bitcoin Transactions Plunge in Cost Amid Ongoing 'Q-Day' Fears

Developers and AI models have made significant strides in optimizing the code behind quantum-safe Bitcoin transactions, leading to an estimated cost reduction of nearly 80% in a single week. The price of constructing such a transaction has plummeted from around $320 to roughly $67 in GPU compute.

The Quantum-Safe Bitcoin Optimization Challenge, run by StarkWare alongside Yukon Research and Eigen Labs, allowed developers to compete and push the number down. The first quantum-safe Bitcoin transaction was mined on mainnet last month, requiring about 3,100 GPU-hours and costing around $320 to build.

Solvers made dramatic progress in the competition, with one core benchmark jumping from 146 million verified candidates per second to over 820 million on a standard RTX 4090. The leading records were held by developers running AI models, with Anthropic's Opus 5 and Fable 5.1 at the top and OpenAI's GPT-6 Astra, Grok 4.6, and Kimi close behind.

StarkWare emphasized that the effort doesn't make Bitcoin quantum-safe on its own, as the transactions are nonstandard and must be sent directly to a miner. The construction only shields coins whose public key hasn't already been exposed, and a soft fork remains the better long-term fix.