BB84 eavesdropping is detectable
Theorem.BB84 eavesdropping is detectable — matching bases ⇒ QBER = 0; intercept-resend ⇒ expected QBER = 1/4 — the eavesdropper is visible.
Proof.matching bases give a shared key with ZERO error while an intercept-resend eavesdropper injects ~25% error on the sifted bits — detectable by no-cloning, the basis of quantum cryptography (Bennett–Brassard 1984).
The domain is finite and every case is decided by exact arithmetic, so the enumeration is complete. ∎
src/9/1/index.ts#discoveredTheoremsWaveFortyFour
1 · Classification
finite-complete — self-contained computation, no external lean
2 · Provenance
Documented theorem re-derived by exhaustive computation (humanityNovel=false); first-in-this-registry is the only sense of discovered.
Acknowledgment
"BB84 eavesdropping is detectable" is a re-derivation, acknowledged to documented mathematics — the original proof is the prior art this re-derivation acknowledges; not new to humanity — the contribution is the reproducible computation discoveredTheoremsWaveFortyFour.
- Prior art
- documented mathematics — the original proof is the prior art this re-derivation acknowledges
- Novelty
- not new to humanity — a re-derivation (humanityNovel = false)
- Contribution
- a reproducible computation (discoveredTheoremsWaveFortyFour @ src/9/1) that re-derives the result at zero tokens — the contribution is the verifiable recomputation, NOT the theorem
3 · Reproducibility
Recompute from source: npm run theorems:verify recomputes discoveredTheoremsWaveFortyFour (src/9/1/index.ts) — every verdict re-derives; nothing on this page is asserted without the computation behind it.