This used only to have one key, but things are slightly more complex at the moment. Our OLD KEY expired in July 2008, but it's the one whose fingerprint and ID are on our business cards. There are quite a few of those out in the wild, and I don't intend to reprint them until the old ones are used up.

But our NEW KEY is the one used to sign all invoices, effective 1.7.2008 (signing date). This key is signed with the old key.

So if you're just here to get the invoice-signing key, and you either don't care about authenticating the key or already have a trusted copy of our old key, you just need the NEW KEY. If you want to authenticate our new key, and you have a business card, then at the moment you need the OLD KEY as well.

Hope that's clear.