The projected computational work required for a critical phase of a potential future quantum assault on Bitcoin and Ethereum has decreased by more than half compared to a benchmark released by Google in March.
A study shared with CoinDesk by experts from the Ethereum Foundation, Theta Labs, StarkWare, and several additional entities details a quantum circuit utilizing 1,151 logical qubits—representing the foundational operational units of such a device—alongside roughly 1.3 million Toffoli gates, which serve as a metric for the computational workload.
Consider these two values as machine scale and job complexity, where a reduced qubit count denotes a smaller device, while fewer gates indicate a lighter workload for that hardware.
The novel circuit achieves a score of roughly 1.5 billion, which sits more than 50% lower than the approximate 3 billion benchmark published by Google Quantum AI during March. The publication noted, however, that the evaluation is not entirely direct since the respective architectures utilize distinct interfaces and accounting metrics.
Read More: Originally published at https://www.coindesk.com/tech/2026/09/10/crypto-researchers-cut-bitcoin-and-ethereum-quantum-attack-estimate-by-50.
