Hardware-Oriented Hidden-Code-Sampling-Inspired Certification on a 60-Qubit Superconducting Processor

Preprint; not peer reviewed.

We report a hardware-oriented quantum sampling experiment motivated by Hidden Code Sampling (HCS), while explicitly not claiming an end-to-end implementation of the original HCS PeakVerification–SyndromeVerification protocol.

A full-width 60-qubit circuit derived from a sparse trivariate-bicycle CSS construction was embedded without swaps on a 108-qubit superconducting processor and compiled to native RX, RZ, and controlled-Z operations. The base circuit contains 180 logical two-qubit rotations and 360 native controlled-Z gates. Local unitary folding produced stress instances with factors 1, 3, and 5, containing respectively 360, 1080, and 1800 controlled-Z gates.

A pilot run was used only to identify and freeze an endian-corrected two-feature local parity witness. The confirmatory dataset consists of three completed QPU executions at folding factors 1, 3, and 5. The final analysis includes only execution records whose frozen QASM identities and authorization hashes match the preregistered confirmatory panel.

Each science circuit received 10,000 shots, and each of four calibration patterns received 4,000 shots in both the pre- and post-experiment calibration periods. Simultaneous finite-shot lower confidence bounds combine Clopper–Pearson calibration intervals, a pre/post drift hull, inverse assignment-channel correction, an empirical Bernstein bound, and worst-case optimization over the calibration box.

The certified margins are 0.2953, 0.2858, and 0.3148 at folding factors 1, 3, and 5, respectively. All three folds pass, and the maximum calibration-parameter drift is 0.0065. Within a preregistered classical attack suite, the conditional operation-count gap is γ = 6.555, above the registered target of 6.0.

This result is an operation-count certificate relative to the registered classical attacks. It is not a wall-clock quantum advantage claim, not a full-distribution total-variation certificate, and not an experimental implementation of the exact HCS protocol.

Quantum circuits were submitted to the Rigetti Cepheus-1-108Q superconducting processor through the Open Quantum platform, operated by Quantum Rings, using the Open Quantum Python SDK. This acknowledgment does not imply endorsement by Quantum Rings of the findings, interpretations, or conclusions reported in this work.

The deposited files include the preprint, LaTeX sources, sanitized confirmatory QASM files, aggregate certificate metrics, integrity manifests, and publication-compliance documentation. Authentication credentials, account metadata, organization identifiers, provider job identifiers, private provider records, and the private audit archive are excluded.