Sun Jan 21 11:33:48 EST 2018

Sensor messages

Don't roll your own crypto.  Though it appears I have to.
Application: remote sensor.  I want to implement this in a way that
does not trust the host it is plugged into.

This is a temperature sensor.
Snooping is not a problem (for now).

However, authentication is.

I'm thinking about HMAC, which needs protection against replay.

Both sides can be made to maintain state, however it would be great to
avoid this on the sensor side.

Time stamps cannot be trusted when they are initialized from the host.