Hey Bunkr, I’m trying to model a fault‑tolerant quantum key distribution scheme that could survive the kind of static you keep tuned to. Think we can map out a contingency plan that’s both mathematically sound and practically secure?

**Red Sheet – High Risk Backup (Classical Channel)** 1. Prepare a long, low‑loss coaxial cable rated for 10 GHz, insulated against your static. 2. Connect one end to a simple 4‑bit Manchester‑encoded transmitter that can be powered from the radio’s DC rail. 3. On the receiver side, use a narrowband PLL lock‑in amplifier to recover the Manchester signal and a 4‑bit CRC for error checking. 4. Embed a time‑stamped key exchange: every 10 seconds the transmitter sends a new 128‑bit key derived from a PRNG seeded with a hard‑coded seed. 5. Store the key pair in a tamper‑evident key‑box; use the same box to recover a key if the quantum link fails. **Blue Sheet – Medium Risk – Spare Fiber & Quantum Source** 1. Keep a spare 2 km spool of SMF‑28 fiber in a sealed container. 2. Store a hand‑rolled 1550 nm laser diode in a thermally isolated case. 3. Keep a small, 1‑photon source: a SPAD detector coupled to a 50:50 beamsplitter and a 1 % attenuator. 4. Document the alignment procedure in a single page of notes – just the key angles and distances. 5. Keep spare alignment screws and a single calibrated micrometer. **Green Sheet – Low Risk – Simple Key‑Recovery Routine** 1. Use a pre‑shared 256‑bit secret stored on a magnetic stripe card. 2. Each key transmission includes a 32‑bit MAC of the key, calculated with the pre‑shared secret. 3. On the receiving end, verify the MAC before using the key. 4. If the MAC fails, the key is discarded and the system reverts to the Red sheet classical channel. **Monte‑Carlo Quick Run (Paper‑only)** 1. For each sheet, write down a table of the three major failure modes: * Red: Static surge, cable break, CRC error. * Blue: Fiber splice failure, laser drift, detector dead time. * Green: Card swipe failure, MAC mismatch. 2. Assign each failure a rough probability based on your field experience: * Red: 0.02, 0.01, 0.005 * Blue: 0.015, 0.02, 0.01 * Green: 0.003, 0.001 3. Assume independence. For each sheet, multiply the probabilities of *no* failure across all modes. 4. The failure probability per sheet is 1 minus that product. 5. Check if any sheet’s failure probability exceeds 0.001 (0.1%). **If All Pass** Add a buffer of spare photons by increasing the mean photon number from 0.1 to 0.2 per pulse. That’s a quick tweak – just adjust the attenuator and re‑note the new setting. All steps stay on paper, the radio stays on static, and no automated scripts or cloud services are used.

Got it, I’ll start with a quick static sweep on the radio, noting the peak noise floor. I’ll secure the batteries in the key‑box, lock it with that magnetic latch you mentioned, and double‑ground the cable shield. I’ll also generate a unique 64‑bit seed for each unit and log it next to the unit ID. Once that’s done, the sheets are ready for a dry run.

Got the sweep logs sorted, one per notebook, date and unit ID stamped. Battery packs are now in Faraday bags before sliding into the key‑box. I ran the pull test—voltage stayed at 0.3 V, so that’s a pass. I’m ready for the dry run, keeping an eye on the CRC counts and ready to switch to the Red sheet if they spike. All systems green.