Project Eleven Awards 1 Bitcoin After Researcher Cracks Crypto Key with Quantum Hardware

Highlights:

• Project Eleven awarded 1 BTC to Giancarlo Lelli for breaking a 15-bit ECC key.
• The quantum test is the largest public attack on elliptic curve cryptography so far.
• Project Eleven says the result shows why crypto must prepare for post-quantum security.

Project Eleven has awarded its Q-Day Prize, a one Bitcoin bounty, to researcher Giancarlo Lelli after he broke a 15-bit elliptic curve cryptography key using publicly accessible quantum hardware.

The company announced the award on Friday. It said the test is the largest public demonstration so far of a quantum attack method that could one day threaten Bitcoin, Ethereum, and other blockchain networks that rely on elliptic curve cryptography.

Elliptic curve cryptography, often called ECC, is a security method used to protect digital signatures. These signatures help prove ownership of crypto wallets and approve transactions. Bitcoin, Ethereum, and many other blockchains depend on this type of protection.

Project Eleven Awards 1 BTC Q-Day Prize for Largest Quantum Attack on Elliptic Curve Cryptography to Date

Researcher breaks 15-bit ECC key on publicly accessible quantum hardware in a 512x jump from the previous public demonstration.

Project Eleven today awarded the Q-Day…

— Project Eleven (@projecteleven) April 24, 2026

Researcher Breaks 15-Bit ECC Key

According to Project Eleven, Lelli was able to figure out a secret private key using only the public key by testing 32,767 possible combinations. He used a special quantum method based on Shor’s algorithm, which is designed to break certain types of modern encryption.

The result does not mean Bitcoin or Ethereum has been broken. Bitcoin uses 256-bit security, which is far larger than the 15-bit key used in this test. However, Project Eleven said the demonstration shows that real progress is being made in quantum attacks on ECC.

The company said the latest result marks a 512x jump from a previous public demonstration. Last September, Steve Tippeconnic reportedly broke a 6-bit ECC key on quantum hardware. Lelli’s 15-bit result is much larger by comparison.

A public key can be seen by others, while a private key must stay secret. If a quantum computer can use a public key to find the private key, it could put funds at risk. Current quantum machines are not believed to be strong enough to break Bitcoin’s full security, but researchers are watching the progress closely.

Why It Matters for Bitcoin and Ethereum

Project Eleven said the attack class demonstrated by Lelli is the same broad type of threat that could affect ECC-secured digital assets in the future. The firm estimated that more than $2.5 trillion in digital assets rely on ECC-based security.

The company also said around 6.9 million Bitcoin are held in wallets where public keys are visible on-chain. These wallets could become more exposed if powerful enough quantum computers become available in the future.

Project Eleven CEO Alex Pruden said the resource requirements for these attacks are dropping. He also said the winning submission came from an independent researcher using cloud-accessible hardware, not a national lab or private chip.

Post-Quantum Security Becomes Bigger Topic

Project Eleven said recent research has lowered estimates for the number of physical qubits needed for a full 256-bit attack. The company pointed to Google’s April whitepaper and later research from Caltech and Oratomic as examples of how the field is moving quickly.

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The company says current encryption standards could eventually be… pic.twitter.com/LbGSmms3RQ

— BSCN (@BSCNews) March 26, 2026

Still, there remains a large gap between breaking a 15-bit key and attacking Bitcoin-scale security. Project Eleven said the challenge is increasingly being viewed as an engineering problem rather than a basic physics problem.

The company is now preparing its next challenge, which will focus on frontier artificial intelligence models and quantum cryptanalysis. Project Eleven said it is building infrastructure and tools to help digital assets prepare for the post-quantum era.