GPG Key
GnuPG is the OpenPGP standard for encrypting and signing data and communications.
How to Use GnuPG
List registered keys
List public keys：
gpg --list-keys
List private keys:
gpg --list-secret-keys
Add Keys
gpg --keyserver keys.gnupg.net --recv-keys [key id]
Remove Keys
gpg --delete-keys [key id]