Bitcoin Quantum Alarm Backfires After Google Researcher Challenges Prize

Project Eleven’s 1 BTC Q-Day Prize was meant to sharpen the controversy over quantum threat to Bitcoin and different ECC-secured crypto belongings. Instead, a pointy critique from Google quantum researcher Craig Gidney has turned the competitors itself into the story.

In an April 25 blog post titled “The predictable failure of the QDay Prize,” Gidney, a analysis scientist on Google’s quantum computing group, argued that the successful submission didn’t meaningfully display progress towards a cryptographically related quantum assault. His central declare was blunt: the competition was structured round a benchmark that present quantum computer systems are poorly suited to measure.

Bitcoin’s Quantum Threat Debate Explodes

Project Eleven had introduced yesterday that it awarded the Q-Day Prize to Giancarlo Lelli for breaking a 15-bit elliptic curve key on publicly accessible quantum {hardware}. The group described the consequence because the “largest quantum assault on elliptic curve cryptography to this point” and stated it represented a 512x soar from a previous 6-bit public demonstration.

For crypto markets, the framing mattered. Project Eleven explicitly linked the consequence to the long-term security assumptions behind Bitcoin, Ethereum, and greater than $2.5 trillion in ECC-secured digital belongings.

But Gidney argued that the take a look at could have proved far lower than marketed. Gidney stated he was invited final 12 months to take part within the Q-Day Prize however declined as a result of he seen the premise as flawed. His first objection was that Shor’s algorithm requires quantum error correction for cryptographically significant cases.

“Current quantum computer systems expertise on the order of 1 error per thousand gates, however cryptographically related cases of Shor’s algorithm require billions of gates,” he wrote. “The solely identified solution to cross this chasm is quantum error correction. There are promising quantum error correction experiments being executed, however in the end quantum error correction remains to be a piece in progress.”

That distinction sits on the middle of the dispute. In Gidney’s view, working small non-error-corrected circuits doesn’t present a helpful proxy for breaking real-world ECC keys, as a result of the scaling habits is basically completely different from the methods that will be wanted to threaten Bitcoin-scale cryptography.

His second objection was extra damaging for the prize consequence. Gidney argued that small Shor-style issues can seem to succeed even when the quantum {hardware} isn’t contributing significant computational worth.
The subject, he stated, resembles a joke paper he revealed for SIGBOVIK 2025, the place he claimed to issue all numbers as much as 255 utilizing a quantum pc, solely to point out that the identical success could possibly be reproduced with randomness. He referred to as this the “Falling With Style” drawback.

“For the close to future, the contribution of luck goes to massively outweigh any legit contribution of the quantum pc,” Gidney wrote, quoting the warning he stated he gave when declining to take part. “So I believe the winner in 2026 will likely be whoever did one of the best job at obfuscating how they made themselves unavoidably fortunate. You’re going to seek out your self in a philosophical debate, with 100K$ on the road, over the place precisely the road for a quantum pc ‘actually’ breaking a key’s.”

According to Gidney, that’s successfully what occurred.

He pointed to work by GitHub consumer Yuval Adam, who reportedly changed the quantum calls within the successful submission with random calls and located that the outcomes have been “indistinguishable” from the quantum model. Gidney stated the circuit building itself seemed legitimate, together with its implementation of the ELDPC circuit from Roetteler et al. 2017, however that this made the issue extra refined quite than much less critical.

“You make an accurate circuit, you get the anticipated consequence, you have fun… however you bought the proper reply for the incorrect purpose,” he wrote. “This is a worry that each competent experimentalist is aware of of their bones. It’s why they don’t simply examine that one thing works when it ought to work, they examine that it breaks when it ought to break.”

Project Eleven Defends The Broader Aim

Project Eleven framed the successful consequence as a sensible demonstration of the assault class that might ultimately threaten Bitcoin and Ethereum. In an response, CEO Alex Pruden said the submission confirmed that “the useful resource necessities for any such assault hold dropping” and that the barrier to working such experiments was falling as a result of the work used cloud-accessible public {hardware} quite than non-public or national-lab methods.

The group additionally cited latest theoretical useful resource estimates, together with Google’s April 2026 estimate of underneath 500,000 bodily qubits for a full 256-bit assault and a later Caltech and Oratomic paper that put the determine as little as 10,000 qubits in a neutral-atom structure. Project Eleven argued that whereas the space from 15 bits to 256 bits stays massive, the hole is more and more an engineering drawback quite than a basic physics drawback.

Pruden later acknowledged Gidney’s critique on X, writing that “small factoring issues are a really imperfect yardstick for Q-Day.” Still, he defended the aim of the competitors as an try and bridge a spot between quantum researchers who see speedy acceleration and cryptographers or Bitcoin builders who need stronger proof earlier than treating present methods as near-term susceptible.

“So, since small factoring issues aren’t yardstick for Q-Day, then what’s?” Pruden wrote. “I’ll fortunately take suggestions on how we will higher incentivize open benchmarking in the direction of Q-Day threat.”

A Credibility Problem For Quantum Risk Messaging

Gidney didn’t dismiss quantum threat to crypto outright. In reality, he wrote that there are “legit issues” quantum computer systems may change into cryptographically related earlier than the top of the last decade, pointing to post-quantum migration efforts at firms akin to Google and Cloudflare.

His argument was narrower, however consequential: a weak benchmark can undermine the case it’s attempting to make. If a contest designed to boost consciousness produces a consequence that critics can reproduce with randomness, it dangers turning into ammunition for skeptics quite than a warning sign for the trade.

At press time, BTC traded at $77,750.