Researchers working on a quantum-resistant way to spend Bitcoin have reduced the estimated GPU computing cost to $59, down from about $320 in August. The improvement is substantial, but the number is a benchmark estimate, not the full cost or proof of a production-ready rescue for exposed coins.
What the method does
StarkWare researcher Avihu Levy designed Quantum-Safe Bitcoin, or QSB, to move coins into a hash-based arrangement using Bitcoin's existing consensus rules. StarkWare says the first QSB transaction was mined on mainnet in September, showing that the construction can operate without a soft fork.
The optimization challenge run by StarkWare, Yukon Research and Eigen Labs focuses on the computational search needed to prepare a QSB spend. Reported performance rose from roughly 146 million verified candidates per second to more than one billion on an Nvidia RTX 4090. The estimated GPU cost fell to $67 in September and then $59 by October 13.
The benchmark has strict limits
The $59 estimate excludes Bitcoin network fees and varies with hardware and electricity assumptions. It also does not demonstrate a complete, repeatable workflow for every affected wallet. A holder must prepare the protective structure before a quantum attacker can derive the private key, and miners must be willing to include the nonstandard transaction.
The original report estimated that about 6.04 million BTC have exposed public keys. Exposure does not mean those coins are presently stealable. Today's public quantum computers cannot break Bitcoin's signatures at that scale, and the timing of a cryptographically relevant machine remains uncertain.
Why lower cost still matters
Reducing preparation cost makes testing and contingency planning more practical. It also gives developers evidence that an emergency technique can be improved with software rather than waiting only for new consensus rules. The counterargument is that a specialized rescue method may be harder to coordinate than a network-wide migration, especially for inactive or lost wallets.
The next evidence should be end-to-end demonstrations, broader miner support and independent review of the security assumptions. Until then, QSB is a promising contingency tool, not a guarantee that Bitcoin's quantum exposure has been solved.