My favourite format for auth cookies is auth_tkt: http://www.openfusion.com.au/labs/mod_auth_tkt/ http://www.openfusion.com.au/labs/mod_auth_tkt/ it's widely su

My favourite format for auth cookies is auth_tkt: http://www.openfusion.com.au/labs/mod_auth_tkt/ http://www.openfusion.com.au/labs/mod_auth_tkt/ it's widely supported, and even if you can't find module for your favourite language, it's pretty easy to implement yourself.