Project Eleven awards Q-Day 1 BTC bounty: researchers use a quantum computer to crack a 15-bit elliptic curve key

Project Eleven, a nonprofit organization focusing on research into “Q-Day (Quantum Computer Cracking Blockchain Cryptography Day),” announced on 4/24 that it would award 1 bitcoin as a bounty to independent researcher Giancarlo Lelli. Using a Shor algorithm variant on publicly accessible cloud quantum computer hardware, Lelli successfully cracked a 15-bit elliptic curve key—this is the largest publicly demonstrated quantum attack to date.

Attack Scale and Significance

Project Content Winner Giancarlo Lelli (independent researcher) Attack target 15-bit elliptic curve key, searching 32,767 possible cases Using hardware Publicly accessible cloud quantum computer Algorithm Shor algorithm variant, targeting the elliptic curve discrete logarithm problem (ECDLP) Previous record September 2025 Steve Tippeconnic cracked a 6-bit key (first public quantum hardware cracking) Progress From 6 bits to 15 bits, scaling up by 512x Bounty 1 bitcoin

How far is the real threat from actual Bitcoin?

Bitcoin actually uses the secp256k1 curve, which corresponds to a 256-bit elliptic curve key. While there is still a huge gap from 15 bits to 256 bits, that gap is shrinking at an unprecedented pace:

A white paper released by Google in April 2026 states that the number of physical qubits required to crack a 256-bit elliptic curve key is already below 500k.

Further follow-up research by Caltech and Oratomic reduced that number to about 10k qubits (based on a neutral atom architecture).

Project Eleven CEO Alex Pruden directly pointed out: “The resource requirements for this kind of attack continue to decline, and the threshold for real-world deployment is also falling.”

In other words, the gap from 15 bits to 256 bits is currently viewed in academia as an “engineering problem,” not a “fundamental physics problem.”

Quantum Exposure in Bitcoin’s Ecosystem

About 6.9 million bitcoins are held in wallets whose public keys are exposed on the blockchain—once these addresses have had outgoing transactions, or when old-style P2PK (pay-to-public-key) addresses are used, an attacker with quantum capabilities could obtain the public key and use it to forge signatures.

At today’s BTC price, the potential exposure amount is far greater than $500k. However, “exposure” does not mean “immediately crackable”—it also requires having quantum hardware capable of running the Shor algorithm on a 256-bit key, and completing the cracking before any new outgoing transactions occur at the target addresses.

Industry Response: The Upgrade Pressure of Post-Quantum Cryptography

The real significance of this Q-Day bounty is not that there are attackers who can steal Bitcoin right now, but that it forces the Bitcoin community (and other blockchain systems, wallets, and L2 solutions that use secp256k1 or similar ECC algorithms) to accelerate their post-quantum cryptography (post-quantum cryptography, PQC) migration plans. Related discussions have become a standard topic in the Bitcoin 2026 Complete Guide and in the L2/wallet development community in recent times.

In the short term, most Bitcoin wallets reduce the time their public keys are exposed on-chain by using hashed-wrapped addresses (P2PKH, P2WPKH, P2TR). The truly fundamental solution still requires protocol upgrades to enable post-quantum signature algorithms—one of the most important security engineering issues for blockchain infrastructure over the next 2–5 years.

This article about Project Eleven awarding the Q-Day 1 BTC bounty for research into using quantum computers to crack 15-bit elliptic curve keys first appeared in Chain News ABMedia.