If your Gnu Privacy Guard or GPG or GnuPG key has been compromised or something has gone wrong, you can revoke your key. Make sure that you generated a revocation certificate and stored in a safe place to do so.
To revoke a key, open a terminal in Linux, and enter the following command:
gpg --import /home/user/revoke.asc <enter>
where revoke.asc is the revocation certificate file name.
As part of good key management practice, you should try not to delete keys, but revoke them.
After you have revoked the key, you need to send it to a key server, so that everyone who used it, knows that you have revoked the key.