StarkWare Cuts Quantum-Safe Bitcoin (BTC) Transaction Cost 79% to $66

79% Cost Cut in One Week

An open optimization challenge run by StarkWare, Yukon Research and Eigen Labs has cut the estimated cost of preparing a quantum-resistant Bitcoin transaction by roughly 79% in a single week, according to the company's Sept. 23 update. The estimate on the public dashboard fell from about $320 — the computing bill behind the first quantum-safe transaction mined on the network in August — to $66 as of this writing. Sixty-two accepted improvements across the two computational stages needed to build such a transaction produced the drop, with most participants relying on AI coding tools to rewrite the search software. The defense, called Quantum-Safe Bitcoin (QSB), operates entirely within the network's existing consensus rules and requires no upgrade, meaning eligible holders could in principle use it today if a cryptographically relevant quantum computer emerged before Bitcoin ships a broader fix. StarkWare frames QSB as an emergency tool rather than a protocol solution: a construction costing several hundred dollars per transaction was a demo, the company wrote, while a bill near $66 approaches something a large holder with unexposed funds might actually pay in a crisis. One caveat stands: the number remains a benchmark estimate, not yet a cost demonstrated by a second mined transaction.

Signature Grinding Explained

StarkWare researcher Avihu Levy published the QSB design in April, describing it at the time as a “last resort measure” given its cost and complexity. The core technique, signature grinding, has the sender burn heavy computation searching for a transaction whose hash happens to format as a valid signature. Bitcoin accepts the result, and its security then rests on the difficulty of reversing a hash rather than on keeping a private key secret — a deliberate choice, because the Shor's algorithm that breaks elliptic-curve signatures has no effect on hash functions. The search happens before broadcast, which is where the extra cost originates. The first QSB transaction was mined and confirmed on Aug. 26, prepared with engineering work from Tomer Giladi and submitted directly through MARA's Slipstream service. It required roughly 3,100 GPU-hours across about 100 graphics processors, around $320 of compute excluding network fees. The public design repository documents the construction, and because nothing in it touches the rule set — no soft fork like SegWit was needed — it fits the proof-of-work network exactly as it runs today.

AI Coding Drives the Speedups

The contest split the work into two stages and runs a public leaderboard. On the same RTX 4090 benchmark card, the leading pinning submission verifies about 881 million candidate values per second against roughly 146 million for the starting code — a 503% gain — while the subset-selection stage improved by 906%. The pinning track alone drew 34 accepted entries from 24 participants, and the leaderboard carries self-reported model labels such as GPT-6 Astra and Opus 5. The arithmetic behind the headline figure, however, is not fully transparent. Our own reconciliation of the published numbers shows the tension: applying the measured speedups — 4.01x for pinning and 5.16x for subset selection, tested on simulated RTX 3090s — to the original $320 breakdown of $15, $80 and $200 across three stages yields about $83. The dashboard states that later record-setting runs exceed those measurement cutoffs without showing which results carry the estimate down to $66. More importantly, the improved code has not yet prepared a second transaction that Bitcoin miners actually packaged, so $66 remains an estimate drawn from benchmark testing rather than a demonstrated, repeatable cost. Readers tracking the market in real time can follow live spot and futures prices on Gate.

Soft Fork Still the Long-Term Answer

Our reading is that the week matters less for the exact dollar figure than for what it signals: moving quantum-exposed coins is becoming an engineering-optimization problem rather than a research problem. The limits are unchanged. QSB cannot protect addresses whose public keys are already exposed — the group a quantum attacker would reach first — and its nonstandard transactions bypass the mempool entirely, forcing direct submission to miners. StarkWare continues to argue that a consensus-level soft fork is the durable answer, and while spot Bitcoin ETF flows dominate near-term positioning, the test to watch is a second mainnet transaction that turns $66 from an estimate into a measurement — proof the emergency exit has actually gotten cheaper for the broader Bitcoin quantum debate.