# Entitlements obfuscation (C)

Shared by `libandroidcast_entitlements.so` and the archived spike under `reference-design/obfuscate_entitlements/`.

- `encode` / `decode` — 40-bit payload + 24-bit verification tag, keyed by per-account `uint64_t` **key** (not wall clock).
- `write_to` / `read_from` — file layout: 32-bit dummy header, N×uint64_t payloads, 32-bit dummy tail.

Reference demo: `tmp/obfuscate_test/` (standalone; not wired into the main app).