Just reporting,
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-arm
Importing GPG key 0xA4D647E9:
 Userid     : "Fedora Secondary Arch (18) <fedora@fedoraproject.org>"
 Fingerprint: 62d6 986a 2639 cf2e 3790 ee45 68dc d160 a4d6 47e9
 Package    : fedora-release-18-0.8.noarch (@anaconda-0)
 From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-arm
Is this ok [y/N]: y


Package libgudev1-195-13.fc18.armv5tel.rpm is not signed
[root@kirkwood-f18-v5tel boot]#