[n_ary]

> Where does that info come from ? If it does come from the "Aircraft Control Domain, or ACD" then these two systems are probably not "completely isolated" as claimed in the article?

You are indeed right, there is a connection to the BUS that shares some information. You can also write back some of the information(flight number, flight leg etc.) back to it. However, rest of the things are read-only. So, no way to do weird things like modifying the altitude or ground speed etc.

Basically, the main computer is completely isolated from the infotainment system, except for the BUS emitting these minor information.

You can however, probably get near the main computer if you can get the jump seat ...

Disclaimer: Work in aviation tech.

[closewith]

> Basically, the main computer is completely isolated from the infotainment system, except for the BUS emitting these minor information.

Unless this is a one-way optical bus or similar, I'd be very skeptical of that claim.

[gruez]

You're making it sound like isolation requires exotic components, but a GPIO pin on a raspberry pi is basically one way only unless you explicitly write code to read data from it.

[gte525u]

FWIW - ARINC429 is a common one way serial bus used in commercial aviation.

[closewith]

Thanks for this comment. It seems that ARINC 429 has been replaced by ARINC 644 in most new aircraft.

From reading the Wikipedia article, they are indeed logically one-way (although the underlying protocol involves two-way communication). It has no security at all.

However, it seems that communication between any avionics systems and anything user-accessible goes through a Network Extension Device (NED). These are required to either be physically (not only logically) unidirectional _or_ have built-in security.

So it might be physically impermeable or it might be a buggy 10-year old firewall. Doesn't exactly inspire confidence given the subject of the article.