Giancarlo Lelli Breaks 15-Bit Elliptic-Curve Key With Quantum Computer, Wins Project Eleven 1 Bitcoin

A quantum computer has broken a 15-bit elliptic-curve cryptographic key in a Bitcoin-related test, and the result has been awarded as a bounty by Project Eleven.

“Summary - Quantum computers are beginning to crack the elliptic curve cryptography used in Bitcoin (BTC)”

bloomingbit

Multiple outlets describe the same core event: Project Eleven awarded its one Bitcoin “Q-Day Prize” to independent researcher Giancarlo Lelli for deriving a private key from a corresponding public key using a variant of Shor’s algorithm.

bloomingbit

The Block says Lelli derived a 15-bit elliptic curve key on a publicly accessible quantum computer, and Project Eleven called it the “largest quantum attack” on elliptic curve cryptography to date.

Cointelegraph similarly frames the work as “the ‘largest public demonstration’ of a quantum computer breaking an ECDSA key,” and it says the attack threatens about $2.5 trillion in value secured by elliptic-curve cryptography algorithms, according to Project 11.

The Quantum Insider quotes Project Eleven’s CEO Alex Pruden saying, “The resource requirements for this type of attack keep dropping, and the barrier to running it in practice is dropping with them,” while also stating that the winning submission came from an independent researcher working on cloud-accessible hardware.

Decrypt reports that Lelli told the outlet, “We should look at it as a sign that technology is moving forward (and that is good), and we should not sleep on it.”

Project Eleven’s demonstration is repeatedly described as a milestone in scale, but not a break of Bitcoin’s real-world cryptography.

Brave New Coin says the quantum computer broke a 15-bit elliptic-curve cryptography key, calling it “a simplified version of the kind of cryptographic system used to secure Bitcoin, Ethereum, and much of the digital asset economy.”

Brave New Coin

It also emphasizes the difference between the demonstration and Bitcoin’s actual parameters, stating that “Bitcoin’s 256-bit secp256k1 cryptography” remains intact and that “A 15-bit key has 32,768 possible values.”

Coinpedia and Decrypt both describe the mechanics as a private-key derivation from a public key using a variant of Shor’s algorithm, and Coinpedia adds that Lelli used “27 physical qubits” and that the process took “about 45minutes.”

The Quantum Insider says Lelli derived a private key across “a search space of 32,767,” and it describes Shor’s algorithm as targeting the Elliptic Curve Discrete Logarithm Problem (ECDLP), the math underlying digital signature schemes securing Bitcoin and Ethereum.

MEXC adds additional specificity about the demonstration’s timeline and hardware, saying Giancarlo Relli achieved the feat on “January 15, 2025,” using publicly available quantum hardware from IBM and that the previous record was set in “September 2024.”

The breakthrough is being treated across outlets as a signal that the timeline for quantum risk is tightening, even while the immediate threat to Bitcoin’s 256-bit security is described as limited.

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Coinpedia

Cointelegraph says the Bitcoin community has “about three to five years to prepare for the quantum threat,” citing analysts at Bernstein, and it reports that Blockstream CEO Adam Back argued that the industry should start preparing post-quantum solutions now even though the threat is decades away.

Cointelegraph quotes Back saying, “Quantum computing still has a lot to prove. Current systems are essentially lab experiments. I’ve followed the field for over 25 years, and progress has been incremental,” and it adds that in March Google published a report showing quantum computers may require far fewer qubits than previously thought to break modern cryptography standards.

Decrypt reports that Project Eleven CEO Alex Pruden told the outlet, “We’re still far, objectively, from the point at which you could actually break Bitcoin,” while also saying, “But how long will it take to close that gap, and will we know the closer we get? I don’t know that we will.”

The Quantum Insider says Google committed to being quantum-secure by 2029, and it quotes Pruden: “Google just committed to being quantum-secure by 2029. The window to get ahead of this is closing.”

Brave New Coin and The Block both describe migration proposals and the idea of freezing or phasing out vulnerable coins, with ForkLog stating that Bitcoin developers and a group of experts presented a draft proposal BIP-361 to “freeze coins vulnerable to quantum computers,” and with Decrypt listing BIP-360 and BIP-361 as migration paths.

Beyond the headline demonstration, several outlets focus on which Bitcoin holdings could be more vulnerable if quantum attacks scale up.

TradingView says quantum computers threaten about “$450 billion in BTC held in older wallet addresses whose public keys are exposed,” and it also notes that the Bitcoin community has “about three to five years to prepare for the quantum threat.”

Cointelegraph

Brave New Coin and ForkLog both cite a figure of “about 6.9 million BTC” in addresses where public keys are already visible on-chain, describing these as more exposed because the public key has been revealed.

Brave New Coin says a Coinbase Quantum Advisory Council paper estimated that “about 6.9 million BTC fall into this more exposed category,” and it adds that with Bitcoin trading near “$77,500,” that implies more than “$530 billion” of BTC sitting in addresses that could become relevant in a future quantum threat model.

ForkLog similarly states that Project Eleven pointed out that about “6.9 million BTC are held in addresses where public keys are already visible on-chain,” and it says those wallets “could become the most vulnerable.”

The Block also reports that Project Eleven said roughly “6.9 million bitcoin are held in wallets where public keys are visible onchain,” and it connects that to the urgency to migrate to post-quantum cryptography.

While the technical demonstration is consistent across outlets, the framing of urgency and market implications varies, and some coverage explicitly ties the event to prediction markets and trader expectations.

“A quantum computer broke a 15-bit elliptic curve key in a Bitcoin-related test”

Crypto Briefing

Crypto Briefing says the demonstration “doesn’t immediately threaten Bitcoin’s 256-bit security but raises questions about future vulnerabilities,” and it describes a “hack market” that is “stable at 100% YES, with traders fully expecting a significant breach by year’s end.”

Crypto Briefing

It also reports that “The Ethereum market shows no reaction,” while also giving a specific odds figure: “Odds for the price falling below $2,000 on April 24 are at just 0.1% YES.”

Cointelegraph and The Block both emphasize that the demonstration is far below real-world cryptographic standards, with The Block stating it “remains far below real-world cryptographic standards.”

Brave New Coin and Decrypt both highlight that the industry is already moving toward post-quantum cryptography, with Decrypt listing BIP-360 and BIP-361 and saying “the Ethereum Foundation has formed a post-quantum security team, and co-founder Vitalik Buterin has outlined a roadmap to replace vulnerable parts of Ethereum’s cryptography.”

Looking ahead, Project Eleven says it is developing its next challenge focused on “the intersection of frontier AI models and quantum cryptanalysis,” and multiple outlets tie that to the idea that AI could accelerate quantum error correction or help identify weaker cryptographic targets.