Unique TKTAuthToken when using VirtualDocumentRoot

[electricBonfire]

I am using VirtualDocumentRoots in my Apache setup: http://httpd.apache.org/docs/2.2/vhosts/mass.html

Is it possible to create a unique TKTAuthToken for each Virtual Host?

For example:

foo.example.com -> /home/sites/foo - accessible by users with "foo" token
bar.example.com -> /home/sites/bar - accessible by users with "bar" token

Here is my conf:

<VirtualHost *:80>
    ServerAlias *.example.com
    VirtualDocumentRoot "/home/sites/%1/
    TKTAuthPublicKey /home/private/tkt_pubkey_dsa.pem
</VirtualHost>

<Directory "/home/sites/*">
   Order allow,deny
   AuthType mod_auth_pubtkt
   TKTAuthLoginURL http://login.example.com/
   TKTAuthTimeoutURL https://login.example.com/?timeout=1
   TKTAuthUnauthURL https://login.example.com/?unauth=1

   TKTAuthToken "?" - Unique for each site

   require valid-users
</Directory>