Back

IBM Quantum Hardware’s Reported 15-Bit ECC Key Break Draws Skepticism From Bitcoin Developers

Project Eleven said Giancarlo Lelli used public quantum hardware and a Shor algorithm variant to crack a 15-bit ECC key, while Bitcoin developers disputed the result’s significance and warned it does not indicate an immediate threat.

BTC

Fact Check
The claim is strongly supported by the Project Eleven press release on PR Newswire, which directly says the company awarded Giancarlo Lelli a 1 BTC bounty for breaking a 15-bit elliptic curve key on publicly available quantum hardware and describes it as the largest quantum attack on elliptic curve cryptography to date. CoinDesk independently corroborates the same core facts in 'Researcher wins 1 bitcoin bounty for 'largest quantum attack' on underlying tech,' including that the hardware was publicly accessible and that the demonstration was framed as the largest public example so far. While a direct Project Eleven website page or official X post was not successfully retrieved in this run, the combination of the official press release and independent reporting makes the claim likely true.
    Reference: 12
Summary

Project Eleven said researcher Giancarlo Lelli won its 1 Bitcoin Q-Day award after cracking a 15-bit elliptic curve encryption key on publicly accessible quantum hardware using a variant of Shor’s algorithm, solving one target from 32,767 possible keys. The reported result, described as a proof-of-concept benchmark and a 512-fold improvement over the prior public result in seven months, drew skepticism from Bitcoin developers, who argued the same outcome could be reproduced with random bits and therefore may not represent a meaningful cryptographic breakthrough. While the test involved a tiny key size rather than production-grade cryptography, the issue is closely watched because elliptic curve cryptography secures Bitcoin signatures and other digital systems. Project Eleven also said about 6.9 million BTC in static addresses remain vulnerable to future quantum threats, while Bitcoin’s proposed BIP-360 aims to introduce quantum-resistant addresses.

Terms & Concepts
  • Shor algorithm: A quantum algorithm designed to solve certain mathematical problems much faster than classical methods, making it relevant to the future security of current public-key cryptography.
  • ECC (elliptic curve cryptography): A public-key cryptography method based on elliptic curves, used to secure digital signatures and other authentication systems.
  • BIP-360: A proposed Bitcoin Improvement Proposal aimed at introducing quantum-resistant addresses to reduce potential risks from future quantum attacks.