Project Eleven, a firm specializing in post-quantum security for digital assets, presented its Q-Day prize – a reward of one bitcoin – on April 24 to Giancarlo Lelli, an independent researcher who managed to crack a 15-bit elliptic curve cryptography (ECC) key from publicly accessible quantum hardware in the cloud.
The organization rates the result as the largest public demonstration to date of the type of attack that threatens BitcoinEthereum and over $2.5 trillion in digital assets backed by ECC.
According to the firm, Lelli derived a private key from his public key in a search space of 32,767 possibilities, using a variant of Shor’s algorithm. That algorithm points to the Elliptic Curve Discrete Logarithm Problem (ECDLP), the mathematical basis of the digital signature schemes that protect Bitcoin, Ethereum and most of the blockchain networks. The firm points out that the achievement did not come of “a national laboratory or a private chip,” but rather a researcher operating with available commercial resources.
It is necessary to emphasize that quantum computing remains in an experimental stage, still lacking domestic applications commercials. Given that current systems are limited to laboratories and specialized centers, it is possible that, despite the firm’s statements, progress depends on proprietary technology with restricted access.
Quantum attacks on ECC have moved from theory to practice in the last seven months. The 6-bit demo made by Steve Tippeconnic in September 2025 It was the first public breakout about quantum hardware; Lelli’s 15-bit result beats it by a factor of 512. Project Eleven notes that the pace of progress exceeds previous industry projections.
The gap that separates the Bitcoin laboratory
Theoretical resource estimates for a full 256-bit attack—the scale at which Bitcoin operates—have fallen sharply over the same period. Google’s April 2026 whitepaper put the requirement at less than 500,000 physical qubits, and a later paper from Caltech and Oratomic reduced that figure to 10,000 qubits in a neutral atom architecture. The organization states that the distance between the 15 bits demonstrated and the 256 bits used by Bitcoin is still considerable, although he maintains that the gap is increasingly reframed as an engineering problem and not fundamental physics.
Project Eleven is a company that develops infrastructure and security tools for the post-quantum era, with a focus on the digital asset ecosystem. Its CEO, Alex Pruden, has argued that a quantum breakthrough could alter the very foundation of cryptocurrencies and “breaks the entire philosophical model of crypto ownership,” referring to the possibility that any actor with sufficient quantum capacity can derive private keys from public keys exposed on chain. The firm has a direct commercial interest in the adoption of post-quantum solutions.
According to Project Eleven data, approximately 6.9 million bitcoin are in wallets whose public keys are visible on the chain, exposing them to an eventual quantum attack. If a quantum computer could derive private keys from exposed public keys, it would fundamentally compromise the security model underpinning cryptocurrency systems, analytics firm Chainalysis previously warned. All blockchains that use ECC share a similar exposure.
The CEO of Project Eleven maintains that the result of the Q-Day Prize confirms that the migration to post-quantum cryptography cannot be postponed: Google has committed to being quantum secure before 2029, and the organization warns that the window to anticipate that transition is closing.