Claude Mythos 5 Helps Cut Quantum Circuit Gates by About 17-Fold

Anthropic published research Oct. 16 on Claude Mythos 5 helping design a point-addition circuit for elliptic-curve calculations that used about 17-fold fewer Toffoli gates than an earlier design, while requiring 12% more qubits.

The new circuit used 4 million Toffoli gates and 935 qubits. The earlier design used 70 million gates and 838 qubits. The comparison shows a trade-off between the two resource measures: fewer gates came with a higher qubit count.

A preprint was posted Oct. 15. Researchers gave the model plain-language descriptions of computational tasks, then used an automated evaluator to check whether proposed circuits worked and score their resource use. The evaluator measured Toffoli gates and peak qubit use.

The search for the point-addition design ran for 53 hours. It began with an initial brief and included occasional prompts for the model to explore more broadly.

Across the broader study, seven of eight tasks reduced both gate and qubit counts against their comparison designs. The tasks covered quantum optimization, numerical computation, chemistry, simulation and number theory. The study also proposed a reversible way to perform modular inversion for elliptic-curve calculations.

Elliptic-curve point addition is a core step in discrete-log algorithms that a sufficiently large quantum computer could run. The findings are circuit resource estimates; they do not describe a run on quantum hardware or an attack on deployed cryptography. Coinbase has also called for early Bitcoin quantum-security planning.

Researchers ranked the designs using the product of Toffoli-gate count and peak qubit use. Circuit depth, routing and hardware constraints can also affect which design is preferable, so the gate and qubit counts alone do not settle how useful a circuit would be on a particular quantum computer.