Once you have local gpg key pair, you can import the unknown key to your local users set of keys. In my case, the key 5CC908FDB71E12C2
needs to be imported as follows.
gpg --recv-keys 5CC908FDB71E12C2
--recv-keys key IDs: Import the keys with the given key IDs from a keyserver.
If you have not already created your own gpg key database for your local user.
gpg --full-gen-key
-full-gen-key: Generate a new key pair.