yum - "Public key not available for ..."

[John Burton]

Greetings!

Arrg... instead of banging my head againts the wall for being stupid, I 
decided to ask...

I just tried to install a package (amarok) via yum using 
apt.kde-redhat.org as the repository. I set up the repository as 
specified a http://kde-redhat.sourceforge.net/

i.e.

[kde-redhat-kde-stable]
name=kde-redhat.org (kde-stable)
baseurl=http://apt.kde-redhat.org/apt/kde-redhat/$releasever/stable

I did a "yum list available" and got a listing and found what I wanted. 
Then I did a "yum install amarok". Yum went through the dependency 
checking and came up with a list of packages to be installed. After 
approving the list, yum downloaded the necessary pacakges. So far so 
good. Then yum gave me the following error(s):

public key not available for 
//var/cache/yum/kde-redhat-kde-stable/packages/amarok-xine-1.1.1-0.2.3.kde.i386.rpm
public key not available for 
//var/cache/yum/kde-redhat-kde-stable/packages/amarok-gstreamer-1.1.1-0.2.3.kde.i386.rpm
public key not available for 
//var/cache/yum/kde-redhat-kde-stable/packages/amarok-1.1.1-0.2.3.kde.i386.rpm
public key not available for 
//var/cache/yum/kde-redhat-kde-stable/packages/libtunepimp-0.3.0-0.fdr.0.3.i386.rpm
public key not available for 
//var/cache/yum/kde-redhat-kde-stable/packages/taglib-1.3.1-0.fdr.1.3.i386.rpm
public key not available for 
//var/cache/yum/kde-redhat-kde-stable/packages/libmusicbrainz-2.1.1-0.fdr.0.3.i386.rpm

Apparently I need the public key for the repository...

I recall reading instructions on how to install a public key for a 
repository, but for the life of me, I can't find / remember them. I 
looked through the Yum man pages, but I couldn't find any mention of it. 
Can anyone give me pointers on how to do it or where to find the info?

John