Key Takeaways
- Deciphering 15-bit elliptic curve keys using a common quantum computer
- From theory to practice: 512 times better in decoding ability in 7 months
Quantum Code Breaking Examples
Project Eleven, a company that formulates solutions to the risks presented by quantum computers to digital assets, announced on April 24, 2026, that independent researcher Giancarlo Relli has cracked an elliptic curve key with 15 bits in a generally accessible quantum computer.
Relli explained that he won 1 BTC (worth 12.4 million yen). He said that this demonstration is currently the largest public threat carried out against the elliptic curve cryptography (ECC) used in cryptocurrencies.
Project Eleven said in its announcement that attacks on ECC have moved from just theories to actual practice over the past seven months. In September 2025, a report on the cracking of 6-bit ciphers on quantum hardware was published. Relli said his efforts improved his results by 512 times during that time.
On the other hand, some comments say that the elliptic curve cryptography of bitcoin has a key length of 256 bits and it will take time for quantum computers to become a real threat to the cryptocurrency.
Project Eleven acknowledged that the difference between 15 and 256 bits is significant, pointing out that quantum technology is still developing. Though remarking that this difference is not anymore a fundamental physics problem, but becoming a problem of engineering.
The company also mentions that some analysts have demonstrated that the requirements for physical qubits that present threats on 256 bits have been lowered over the past seven months.
Call for Action
Alex Pruden, Project Eleven chief executive, pointed out in the company’s announcement that “the resource requirements for attacks like this one continue to fall, and with it, the barriers to execution are lowering.”
Pruden explained that the demonstration was conducted using hardware that can be accessed via the cloud by independent researchers; the exercise did not use national laboratory equipment or proprietary computer chips.
“This result shows that concrete progress is possible and highlights the urgency of moving to quantum-resistant cryptography immediately,” he added.
