http://vww6ybaluuo4gfuuf6zvlt23hvg2pcfayco5iiwhv3plo6o7bewivoid.onion/zh/security/message-security/openpgp/gpg-best-practices
Make sure you created a separate signing key before you do this, otherwise you will not be able to sign emails without your offline key.
Extracting the primary key is tricky, but this should get you going: # extract the primary key
gpg -a --export-secret-key
[email protected] > secret_key
# extract the subkeys, which we will reimport later
gpg -a --export-secret-subkeys
[email protected] > secret_subkeys.gpg
# *delete* the secret keys
from the keyring, so only...