SPI Security

[woodz-]

One question: have you thought of securing your SPI comm either?
Couldn't it be a security hole if you provide firmware updates OTA-ly? Hardware could be easily hacked into to manipulate SPI comm.
Wouldn't it be interesting to have secure SPI?
Again, it is just a question and likely far away from reality. But I'd be interested what a sw-dev with profession thinks about.

When I started with Aduino, my naive understanding was: "everything would be run on AVRs". When I'd like to have WiFi, I'd need to order a WiFi module and serially talk to it. This way it would never be possible to secure my comm, since HW-wires are always accessible and there is no out of the box serial securing mechanism on the AVRs.
Very soon I learned, Arduino is far away from this. The IDE supports a lot more than AVR-based HW-boards like the ESPs. Only this way we can have secure comm, by not exposing any HW-wires to the world.