Quantum Device Fingerprint Authentication

A checkpoint and a supply-chain device share a secret reference qubit state — a single point on the Bloch sphere. This simulator sends a stream of photons carrying that state across a channel to the device, lets you dial in an intercept-resend attacker and ordinary channel decoherence, and measures how far the device's returned state drifts from the reference. Because any measurement or tampering of a quantum state necessarily disturbs it, the resulting fidelity and QBER (quantum bit error rate) readouts reveal an eavesdropper or a compromised device statistically — run a verification round to watch the measured Bloch vector, the photon stream color, and the pass/fail authentication readout respond live.