Just out of interest how do you transfer the key between datacentres for setup? Same person travels between them? PGP encrypted email? Or over the phone? Phone

Just out of interest how do you transfer the key between datacentres for setup? Same person travels between them? PGP encrypted email? Or over the phone? Phone is I think an obvious (and now clearly wrong choice) although maybe always suspect if you are concerned with dark fibre . The endpoint security of a device generating and transmitting the key now also being a risk. How far up the chain do you worry? An airgapped device to generate the key and a single person travelling between datacentres seems the secure (although costly) solution. Obviously if TSA/customs remove device from them for inspection or connect it to anything it needs to be thrown away (or moved to insecure duties) and the setup process restarted.