Mirror keys?

Hi,

I've been puzzling over how to set up a push client mirror. Specifically,
how to get hold of the public key for the upstream mirror. I need to put
that key in my authorized key file to allow the upstream mirror to trigger
the sync.

Since what I want is a local copy of the debian-security, I did an nslookup
on security.debian.org, put the resulting IP into a web browser and then
endded up at schein.debian.org. Then searching within db.debian.org I
searched for schein and was able to copy the public key from the resulting
webpage.

This works, but seems a bit convoluted. Also, it doesn't work for a mirror
such as ftp.ca.mirror.org because this server doesn't have an entry at
db.debian.org.

We are encouraged to pull from the mirrors (www.debian.org/mirror/ftpmirror),
shouldn't the keys be easily available? I looked and looked, but I couldn't
find any listing of mirror keys. Am I going about this in the wrong way?

Regards,
Max