Some of the other comments are that a 2G tower tells a phone whether it's allowed on or not, but that the phone doesn't have any verification in the other direc

Some of the other comments are that a 2G tower tells a phone whether it's allowed on or not, but that the phone doesn't have any verification in the other direction. That's just the design of 2G cell networks. It's not an optional setting. Other comments say that LTE networks authenticate in both directions, so you're safe if you can set your phone to LTE-only.