Bitcoin’s quantum-safe protection gets 82% cheaper as researchers race to secure 6 million exposed BTC

Researchers have cut the estimated computing cost of a specialized quantum-safe Bitcoin transaction by 82% to $59.

Data from the Quantum-Safe Bitcoin Optimization Challenge showed that improvements in graphics processing software reduced the projected expense from approximately $320 during StarkWare's first mainnet demonstration in August to $67 in September and $59 as of Oct. 13.

The breakthrough could make a specialized Bitcoin protection method more affordable as developers seek ways to safeguard cryptocurrency holdings against future quantum computers without waiting for changes to the network's underlying protocol.

The public competition, organized by StarkWare, Yukon Research, and Eigen Labs, used AI-assisted coding tools to accelerate the computational searches required for the transactions.

Its latest benchmark recorded more than 1 billion verified candidates per second on an Nvidia RTX 4090 GPU, up from an initial rate of approximately 146 million.

However, the $59 figure remains a hardware-dependent estimate based on simulated GPU workloads rather than a completed production transaction. Bitcoin network fees are separate, while some computing stages still rely on provisional assumptions.

StarkWare said the improvements make its proposed emergency protection method considerably cheaper to prepare, with researchers now targeting a computing cost below $10.

Quantum computing advances intensify Bitcoin security race

The development builds on research by StarkWare's Avihu Levy, who demonstrated in August that Bitcoin could support a quantum-resistant spending arrangement under its existing consensus rules.

Known as Quantum-Safe Bitcoin (QSB), the method uses hash-based cryptography and a computational puzzle to secure specially prepared Bitcoin holdings against attacks on conventional digital signatures.

The approach lets holders do the required calculations off-chain before spending their coins, potentially offering protection while developers work on broader changes to Bitcoin's cryptographic infrastructure.

That research has gained urgency as advances in quantum computing challenge previous estimates of how much computing power attackers would need to compromise cryptocurrency security.

In March, Google Quantum AI reported that future quantum computers could break the elliptic-curve cryptography used by Bitcoin with substantially fewer resources than previously estimated.

Its researchers calculated that certain attacks could theoretically complete in minutes using fewer than 500,000 physical qubits under specified hardware assumptions, a roughly 20-fold reduction from earlier estimates.

Although such machines remain beyond publicly demonstrated capabilities, the findings have increased pressure on blockchain developers to prepare before quantum attacks become practical.

The potential exposure is substantial.

According to a study by Glassnode, approximately 6.04 million BTC, representing 30.2% of Bitcoin's issued supply at the time, had public keys already visible on-chain.

The figure included 1.92 million BTC exposed through their underlying address structures and another 4.12 million BTC exposed through practices such as address reuse and previous spending activity.

A sufficiently powerful quantum attacker could theoretically derive private keys from those exposed public keys and gain control of the associated coins.

The threat has fueled debate over how quickly Bitcoin should adopt quantum-resistant cryptography, particularly given the complexity of introducing changes across a decentralized network.

QSB could offer an interim option, but it protects only eligible coins whose conventional public keys remain hidden until they are moved into specially constructed outputs.

That requirement leaves already-exposed holdings vulnerable if a capable quantum attacker emerges before owners can complete a secure migration.

The method also faces practical deployment restrictions. Although QSB transactions comply with Bitcoin's consensus rules, ordinary network relay policies reject them, requiring direct submission to miners willing to process them.

MARA's Slipstream service provided that route during the August demonstration.

Still, StarkWare continues to favor a broader Bitcoin protocol upgrade for long-term protection. Researchers must now demonstrate the latest computing savings in complete transactions and establish dependable miner access before QSB can become a practical fallback for holders.