I hear you about going back to analog. The problem in the States is that Republicans have managed to gut the postal service and drive up its prices so that normal people can’t afford it. Electronic communication is all they can afford.

PGP encrypts and decrypts locally. Your private keys never leave your device. Public keys are meant to be shared widely, but without the private key, anyone who intercepts the message has exactly a block of encrypted text and no way to read it.