Quick notes on using GPG

gpg-usage-notes.md

Listing keys

gpg --list-keys --with-subkey-fingerprint

gpg --list-secret-keys

Generating a key

gpg --full-gen-key

Remember to save the key password somewhere safe!

Deleting a key

If your keychain has both private & public keys, delete the private key first:

gpg --delete-secret-keys <key-id>

Then delete the public key:

gpg --delete-keys <key-id>

Encrypt & (optionally) sign a message into text file

For encrypting & signing:

gpg --recipient <recipient-key-id> --recipient <your-key-id> --local-user <your-key-id> --sign --encrypt --armor --output encrypted.txt file-to-encrypt.txt

For encrypting:

gpg --recipient <recipient-key-id> --recipient <your-key-id> --encrypt --armor --output encrypted.txt file-to-encrypt.txt

Which produces a file encrypted.txt. Per man gpg, note that --local-user specifies what key to use for signing. You add yourself as a recipient as well, optionally, in order to also be able to decrypt the encrypted message; got this idea from here. Think of the use case where you want to be able to read the encrypted emails you've sent.

Decrypt file

gpg --decrypt encrypted.txt

Export public key into text file

gpg --export --armor <key-id> > my-public-key.txt

Export private key into text file

gpg --export-secret-key --armor <key-id> > my-private-key.txt

Warning Take care in saving this file safely.

Import some public or private key

gpg --import some-key.asc