3 ms·
Nope, the client device only needs the server's public key, which isn't a secret. The session keys are a secret but they're also different for every device, tra
by zrm 6y ago
Nope, the client device only needs the server's public key, which isn't a secret. The session keys are a secret but they're also different for every device, transient and never written to permanent storage.
- creeble 6y agoThen any device can connect to that server, not just authorized devices. Maybe you assume that's okay, but it's an attack vector on the server, and it means someone can emulate a device that isn't really one.
- zrm 6y agoThe device can identify itself with a UUID, which isn't key material and doesn't allow anyone to break the channel between the actual device and the server, which is still authenticated by the client using the server's public key. The attacker could generate a random UUID and connect to the server, but then it just shows up as an unconfigured device and gets ignored. The attacker would have to extract the UUID from the device it wanted to impersonate, which still wouldn't allow it to impersonate any other device the same way a WiFi password does, and would then be detectable because there would be two devices claiming to have the same UUID, at which point you generate a new one for the real device after addressing whatever allowed the attacker to extract it to begin with.