Quantum-result verification

Zeq can act as a verifier of quantum-hardware outputs — only where a checkable ground truth exists, and it says plainly where one does not. There is no universal-verification claim anywhere.

The coverage map (published, honest)

GET /api/quantum-verify/coverage returns exactly what is and isn't verifiable:

Class	Verifiable	Ground truth
bell-chsh	✅	Exact: classical bound S≤2, Tsirelson S≤2√2≈2.8284
deutsch-jozsa	✅	Deterministic: constant ⇒ all-zeros, balanced ⇒ non-zero
bernstein-vazirani	✅	Deterministic: measured == hidden bitstring
grover	✅	Near-deterministic: measured == marked, at high probability
random-sampling	❌	None that is classically efficient — by design
arbitrary-circuit	❌	None without a known expected output

v1 verifies the classes whose ground truth is exact (mathematical / structural) — so there's no curated physics table that could itself be wrong. Random-sampling / "supremacy" outputs return not_verifiable with the reason; we do not pretend to check what is, by construction, unverifiable.

Verdicts + tamper-evident proof

POST /api/quantum-verify { class, input } returns a verdict — confirmed | refuted | anomaly | inconclusive | not_verifiable — and, when verifiable, persists a record with an HMAC proof over the canonical claim. GET /api/quantum-verify/:id recomputes the proof from the stored fields and returns proof_intact — so tampering is detectable.

For CHSH specifically: S ≤ 2 → refuted (classical, no violation); 2 < S ≤ 2√2 → confirmed (valid quantum violation); S > 2√2 → anomaly (beyond Tsirelson — physically impossible, indicates a measurement/analysis error).

Verify it yourself

curl https://zeqstate.com/api/quantum-verify/coverage

curl -X POST https://zeqstate.com/api/quantum-verify -b "$COOKIE" \
  -H 'content-type: application/json' \
  -d '{"class":"bell-chsh","input":{"s_value":2.7}}'
# → { verdict:"confirmed", proof:{ alg:"hmac-sha256", value, verify_hint }, ... }

curl -X POST https://zeqstate.com/api/quantum-verify -b "$COOKIE" \
  -H 'content-type: application/json' \
  -d '{"class":"random-sampling","input":{}}'
# → { verdict:"not_verifiable", persisted:false }  (honest — not recorded)

Source: shared/api-core/src/lib/quantumVerify.ts, routes/quantumVerify.ts, app/lib/db/src/schema/quantum-verifications.ts.