Post-quantum startup Project Eleven has awarded 1 BTC (~$77,736 at writing) to independent researcher Giancarlo Lelli for the largest demonstration yet of a quantum attack on Elliptic Curve Cryptography (ECC). Using a publicly accessible quantum computer, Lelli derived a 15-bit elliptic curve private key from its public key in about 45 minutes, employing a variant of Shor’s algorithm to crack the elliptic-curve discrete logarithm problem (ECDLP) — the foundation of Bitcoin and Ethereum digital signatures.
512x Search Space Boost, Still Far From Bitcoin
The break represents a 512x increase in total search space complexity, or 32,768 possible private key combinations, with only one correct. It surpasses the previous record — a 6-bit crack achieved in September 2025 by Steve Tippeconnic. Still, a 15-bit hack is negligible against Bitcoin’s 256-bit ECC. Lelli used 27 physical qubits, while Google estimates breaking Bitcoin would require 10,000 to 500,000 physical qubits.
AI May Accelerate Quantum Threats, Tech Giants Set 2029 Deadline
Advances in artificial intelligence could enable stable, high-performance quantum computers, which might then be used to scale up quantum attacks on Bitcoin and other blockchains. IBM, Microsoft, and Google are among the leading firms researching quantum tech. Google has set 2029 as a deadline for post-quantum cryptography to mitigate risks.
Most Vulnerable: 6.9M BTC in Legacy Addresses
Addresses with exposed public keys are most at risk, including legacy (P2PK) addresses holding a total of 6.9 million BTC, reused addresses, and those that have transacted via Bitcoin’s Taproot upgrade. Bitcoin’s 10-minute transaction confirmation window makes public keys visible, creating a quantum attack opportunity. Decentralized blockchains face greater coordination challenges for quantum-proofing than banks, which can implement top-down security updates overnight. Cryptographic systems must now evolve to protect a $2.6 trillion industry.