To check the GnuPG signature of an RPM file after importing the builder's GnuPG key, use the following command (replace <rpm-file> with the filename of the RPM package):

rpm -K <rpm-file> 

If all goes well, the following message is displayed: md5 gpg OK. This means that the signature of the package has been verified, that it is not corrupt, and therefore is safe to install and use.