Bitcoin's Quantum Insurance Policy Just Got 79% Cheaper

Bitcoin has a quantum problem: a sufficiently powerful quantum computer could one day break the elliptic-curve signatures securing the network, potentially letting attackers steal coins whose public keys are exposed. An experimental backup plan — designed to work without changing Bitcoin's consensus rules — just became dramatically cheaper to use.

According to StarkWare, a weeklong optimization challenge cut the estimated GPU cost of preparing a quantum-resistant Bitcoin transaction by about 79%, bringing it below $67 — the public dashboard now shows around $66. That's down from roughly $320 in compute spent on the first such mainnet transaction in August.

A demo becoming a tool

"A construction that costs a few hundred dollars per transaction is a demo," StarkWare wrote in its September 23 update. "One that costs $67 is closer to something a holder with a large unexposed balance might reach for in an emergency."

The design, called Quantum-Safe Bitcoin (QSB), was published in April by StarkWare researcher Avihu Levy. It adds hash-based protection against quantum attacks without touching the network's consensus rules. Levy himself has called it a "last-resort measure" given its cost, complexity, and limited applicability — while continuing to argue for protocol-level changes as the real answer.

The first QSB transaction was mined and confirmed on August 26, with engineering by Tomer Giladi and direct submission through MARA's Slipstream service. Preparing it took roughly 3,100 GPU-hours across about 100 GPUs, costing around $320 in compute, excluding network fees. To bring that down, StarkWare, Yukon Research, and Eigen Labs launched the optimization challenge on September 16, inviting developers, researchers, and AI agents to make the transaction-building software faster. The result: 62 accepted improvements across the two computational tasks needed to prepare a QSB transaction.

Caveats remain

The new cost figures come from benchmark tests — the optimizations haven't yet been demonstrated on a live transaction. And StarkWare still says a soft fork to Bitcoin's consensus rules would be the better long-term answer for broad quantum protection.

But the trajectory is clear: a defense that cost hundreds of dollars per transaction a month ago now costs tens. In a year when quantum risk has moved from academic curiosity to boardroom concern, even a last resort is getting more practical.

Crypto prices are volatile and the figures above reflect the reporting of the cited sources at the time of publication.

Written by the BidAsk Newsroom. Based on reporting from the sources below.