The CAN write gate (page-42/43 challenge/response) is a 32-round TEA/XTEA-family
Feistel keyed by a per-session 32-bit key; REMOTE_CONTROL = 0xB16B00B5. Verified
51/51 against captured challenge/response pairs across nodes 2A/61/75/F8 (one
global key, not per-node), so the CAN path can now actuate, not just sense.
- ids_can_auth.py Python reference + self-test (51/51)
- esphome/ids_can_auth.h C++ port for the ESP32 node (host-tested 8/8)
- sniff/analyze_auth.py structural analysis (rules out affine; confirms keyed cipher)
- sniff/auth-pairs-multinode-2026-06-11.txt +9 pairs across 4 nodes
- README document the cipher, session keys, unlock sequence
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
