---
type: concept
tags: [parking, security, platform]
sources: [parking-system-architecture]
updated: 2026-06-21
---

# Disk / OS Hardening

Worthwhile, but **not the main event** — it defends against the outsider-with-physical-access,
not the operator (see [[threat-model]]). (See [[parking-system-architecture]] §3.)

Physical-access attacks on Windows are trivial (boot media + password-reset tools), so a
**dedicated Linux machine is the correct platform** — not Windows or WSL. This is a
[[standing-decisions|standing decision]].

- **LUKS full-disk encryption** — defeats boot-from-USB.
- **GRUB password + Secure Boot** — prevents boot-parameter tampering / unsigned loaders.
- **No desktop environment** — single-purpose appliance.
- **Key-based SSH only.**
- **[[tpm|TPM 2.0]]** _(recommended, 2026-06-21)_ — seals the LUKS key to the boot chain so the disk
  **auto-unlocks only on an untampered boot**, making encryption-at-rest compatible with **unattended
  reboot** (a booth must come back up after a power cut without a human typing a passphrase). Also a
  candidate home for the non-extractable host event-signing key. Caveats (live-root limit, bus-sniff,
  PCR brittleness, mandatory recovery passphrase + re-seal runbook) on [[tpm]]; implementation is
  [[open-questions]] #12.

With LUKS in place, **SQLCipher becomes optional** defence-in-depth rather than the critical
layer. (The custom controller adds its own: ESP32 flash encryption + secure boot — see
[[esp32-custom-controller]].)