I'm not familar with SSH certificates, but I do know the fundamentals of certificate-based authentication. If you don't have a way to revoke the cert, then the

I'm not familar with SSH certificates, but I do know the fundamentals of certificate-based authentication. If you don't have a way to revoke the cert, then the server will assume that your properly signed unexpired certificate is valid. You will need some way to let the server know that the previously issued cert is not valid anymore. This is how this type of authentication works, and the article did not address the important case of wanting to revoke a user's credentials.