Researchers working with AI coding agents have significantly reduced the computing resources required for a key step in a potential quantum attack on Bitcoin and Ethereum's cryptography, according to a paper released Wednesday.
The challenge, known as ECDSA.Fail and launched by Eigen Labs in late May, tasked more than 100 participants with designing quantum circuits for secp256k1, the elliptic curve that secures transaction signatures on both blockchains. By July 26, participants had cut the resource benchmark by 86%, reducing it from 10.75 billion to 1.496 billion.
The leading circuit design used 1,151 logical qubits and approximately 1.3 million Toffoli gates, quantum operations that are computationally expensive. The resource score was calculated by multiplying logical qubits by the number of Toffoli gates required, with a lower score indicating fewer combined resources needed for the calculation.
A later design brought the gate count below 1 million. The researchers noted that their findings represent roughly half of Google Quantum AI's March benchmark, though differences in testing methods prevent direct comparison. The tests verified the circuit's calculations but did not crack an actual Bitcoin private key.
The paper's authors are affiliated with Theta Labs, MultiVM Labs, Eigen Labs, Trail of Bits, StarkWare, and the Ethereum Foundation.
The research underscores ongoing uncertainty about when quantum computers will become powerful enough to execute a full attack on current cryptography, a milestone termed "Q-Day." The researchers noted that migration away from vulnerable cryptography is already underway, with NIST having standardized post-quantum replacements and proposing deprecation of classical public-key algorithms at the 112-bit security level after 2030 and disallowing them after 2035.
The findings come as crypto companies increase investment in quantum defense research. In July, Galaxy Digital committed up to $5 million to quantum security work, while nine firms including BlackRock and Coinbase pledged a combined $15 million over three years for broader Bitcoin security research that includes quantum defenses.
