On: Hacker told FBI he made plane fly sideways after cracking entertainment system

[koonsolo]

First you say it uses isolated networks, but then you say NED connects the two? How does it enforce the 'one-way'?

[neurotech1 → koonsolo]

There is multiple networks for the various aircraft systems not a single network.

The NED for the IFE doesn't physically have the wires for two-way connectivity to the aircraft FMS network.

[vidarh → koonsolo]

With no knowledge of how these systems are actually implemented for aircraft, for various values of "isolated":

I once had a customer that provided energy pricing data from their network via a leased line to be put onto their website. In their case the isolation they required was provided by not running any network stack over that link - they sent a mostly raw (error correction but that was it) stream of data point to point rather than network packets, and the connection was entirely one-way - if we were to try to send anything back, nothing was listening.

Making it physically impossible for something to listen is reasonably straight forward if you control the hardware, and you can easily additionally electrically isolate the networks.

[EliRivers → koonsolo]

While I have no idea how they do it, I used to do it with one of these: https://en.wikipedia.org/wiki/Opto-isolator

One circuit emits light, the other circuit listens to the pattern.