How to get a nodes fields in hook_init() ?

I want to give anonymous users a chance to sign up for an event by filling out a custom form.
Therefore I built a custom content type wit cck. I added the password field to it.
Now I want the (anon) user to enter his password before he starts editing his entry.
The original password-module is my base for this mod. Thanks to the securesite-module I managed to get a login-promt via HTTP-AUTH.
I also get back the users data in hook_init(); But I am still missing the original password stored in the node.
What would be the best way to get it from the node?
Alternatively it would be ok to compare the password in hook_access or hook_grant_rights, I think.