Consertando erro de GPG

Se ao rodar um apt-get update houver o erro:

GPG error: http://extras.ubuntu.com maverick Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 123456779WHATEVER

a solução é:

gpg –keyserver keyserver.ubuntu.com –recv 3E5C1192
gpg –export –armor 3E5C1192 | sudo apt-key add -
sudo apt-get update