A story of SMS pagers, secure phone calls, express couriers, and the DNS phonebook that finds the Commander
The Commander has three radio channels to reach every robot. Short commands go by SMS (like a pager). Big deliveries use HTTPS with PSK-TLS (like a secure phone call). Slow networks use CAT_TP (like an express courier over rough roads). Always encrypted, always secure!
For short commands, the Commander uses SMS: like sending a text message. Each message is protected with SCP80 encryption (AES scrambling), carries a digital signature proving it really came from the Commander, and the robot sends back a "Proof of Receipt": like a read receipt!
For big deliveries, the Commander starts with an SMS "wake-up call" and the robot opens a secure PSK-TLS tunnel. Both already share a secret password (SCP81 keys), so no certificates needed! For slow 2G networks, CAT_TP acts like a lightweight courier: same security, less overhead.
When the Key Factory delivers keys, it wraps them in a secret SCP03 box. The Commander carries the box to the robot but cannot open it! Inside the robot, the Commander's Office (ISD-R) passes the box to the right Profile Room (ISD-P). Only ISD-P has the key. A secret message inside another secret message!
The Commander doesn't use normal website certificates for HTTPS. Instead, it uses PSK-TLS: both sides already share a secret password (SCP81 keys). No certificates needed! Plus, robots use DNS like a phonebook to find the Commander's address: so they don't need IP addresses burned in at the factory.