Researchers have cut the estimated computing cost of a specialized quantum-safe Bitcoin transaction by 82%, bringing it down to $59. The drop came from improvements in graphics processing software, which lowered the projected expense from about $320 in August to $67 in September, and then to $59 as of Oct. 13.
The work ran through the Quantum-Safe Bitcoin Optimization Challenge, organized by StarkWare, Yukon Research, and Eigen Labs. Using AI-assisted coding tools, the team pushed throughput past 1 billion verified candidates per second on an Nvidia RTX 4090 GPU — up from an initial rate of roughly 146 million. That's a big jump in raw output for a consumer-grade card.
Where the $59 comes from
It's worth being precise here. The $59 figure is a hardware-dependent estimate based on simulated GPU workloads. It is not a completed production transaction. Bitcoin network fees are separate, and some computing stages still rely on provisional assumptions. So the number is a projection, not a receipt.
The underlying scheme is Quantum-Safe Bitcoin, or QSB. StarkWare's Avihu Levy demonstrated in August that Bitcoin could support a quantum-resistant spending arrangement under existing consensus rules, using hash-based cryptography and a computational puzzle. QSB lets holders perform the required calculations off-chain before spending. In theory, that protects specially prepared Bitcoin holdings against quantum attacks on conventional digital signatures.
Why anyone cares about quantum threats now
The urgency traces back to quantum computing research. Google Quantum AI reported in March that future quantum computers could break Bitcoin's elliptic-curve cryptography with fewer than 500,000 physical qubits under certain hardware assumptions. That's a roughly 20-fold reduction from earlier estimates.
How much BTC is exposed? A Glassnode study found that approximately 6.04 million BTC — 30.2% of Bitcoin's issued supply at the time — had public keys visible on-chain. Of that, 1.92 million BTC was exposed through underlying address structures, and 4.12 million BTC through address reuse and previous spending activity. Those coins are the ones QSB is designed to help.
The relay problem, and MARA's workaround
QSB transactions comply with Bitcoin's consensus rules. But ordinary network relay policies reject them anyway. That means they can't just be broadcast like a standard payment; they need direct submission to miners. During the August demonstration, MARA's Slipstream service provided exactly that route.
So the path exists, but it's narrow. It depends on a miner willing to accept the transaction outside normal relay channels. That's a practical constraint for anyone hoping to move quantum-safe coins in a hurry.
StarkWare favors a broader Bitcoin protocol upgrade for long-term quantum protection. The research group is targeting a computing cost below $10. The gap between $59 and $10 is the next milestone, and it's the number to watch as the optimization work continues.
