For our scenario, I think that shutting down the internet should also involve shutting down anything that uses electricity and any device that uses radio waves for communication except for perhaps the most primitive of radios. However, while the internet shut down should be permanent until the keys are activated, I think that some things using electricity should be able to be restarted.

For example, electric cars or car starters would shut down in the initial event, but they could be fixed by anyone with knowledge of how to fix electronics. However, things like the a city’s electrical grid would be harder to fix due to all radio wave based communication going down alongside the Internet and the sheer complexity of the system.

This would allow us to explain how the device all the keys go into still works because either one of the soldiers at Area 51 fixed it or one of the keyholders has knowledge in electrical engineering. It could even be Wisdom who gets the machine fixed since he was one of the ones to build it.

How does that sound?