Giancarlo Lelli is awarded the Q-Day prize for the largest quantum attack on elliptic curve cryptography
24.04.2026
New York, NY, April 24, 2026 - Project Eleven announced the Q-Day award to independent researcher Giancarlo Lelli for successfully cracking a 15-bit elliptic curve key using a publicly available quantum computer. The achievement was the largest public demonstration to date of an attack on elliptic curve cryptography, which protects more than $2.5 trillion worth of digital assets, including Bitcoin and Ethereum.
Lelli applied a modified Shor's algorithm to solve the discrete logarithm problem on an elliptic curve, allowing him to recover a private key from a public key in a search space containing 32,767 possible values. This achievement is 512 times the previous record set in September 2025, when Steve Tippeconnick cracked a 6-bit key using a quantum computer.
"The resource requirements for these types of attacks continue to decrease, and the barrier to practicing them is also decreasing," said Alex Pruden, CEO of Project Eleven. "The winning submission came from an independent researcher working on cloud-based hardware. This shows that tangible progress is possible and highlights the need to move to post-quantum cryptography in the near future."
While a 15-bit key is significantly smaller than the 256-bit keys used in Bitcoin, the achievement highlights the growing threat that quantum computing poses to current cryptographic standards. It is estimated that around 6.9 million Bitcoins are held in wallets with public keys visible in the blockchain, making them vulnerable to quantum attacks.
Project Eleven continues to develop new challenges centered on the intersection of advanced artificial intelligence models and quantum cryptanalysis, aiming to strengthen the security of digital assets in the post-quantum era.
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