create gpg key pair

gpg --full-generate-key

export public key

gpg --export --armor email@email > key.asc

import public key

gpg --import pub.asc

list public keys

gpg --list-public-keys

encrypt asymmetric (with key)

# or -e        -r
gpg --encrypt --recipient friend@email file

 echo message | gpg --encrypt --recipient email@email | base64 -w0

encrypt symmetric (with password)

# or -c
gpg --symmetric file

 echo message | gpg --symmetric | base64 -w0

decrypt

# or -d
gpg --decrypt file.gpg > file