Generate keys
$ gpg --gen-key
Encryption
$ gpg --encrypt --sign --armor -r recipient_email -r my@email.com file_to_encrypt
Decrypt
$ gpg --output path/to/decrypted/file file_to_encrypt.asc
Create subkey
Backup files
$ umask 077; tar -cf $HOME/gnupg-backup.tar -C $HOME .gnupg
Find key and edit it
gpg --list-keys yourname gpg --edit-key gpg> addkey
Choose the "RSA (sign only)"
entropy stuff
gpg> save