How to establish a company web-of-trust

[Karl Voit]

Hi!

I want to establish secure email communication in our company
(Windows, Outlook, gpg4win). I do not want to maintain a keyserver
by myself.

My attempt: every employee generates his own keypair and exports the
public key to a keyserver. I as the admin downloads his key from the
server, compares the ID with the employee and signs the key with the
"central company key".

Any communication partner can check, wether the key of the employee
was signed by our official "company key" which is downloadable from
our web site.

So far so good - I think.

But: what if an employee quits the company? Can I revoke the
signature? WinPT (as a key management frontend) does not seem to
provide this feature.

Thank you for your ideas!

-- 
Karl Voit