Using username/password for other script

[goregasm]

Hello,

I recently bought another license for a site of mine called goregasm.com . At goregasm.com i use a self written comment-, submission- and registerscript. I'm installing the VBulletin and i want to let the other scripts use the vbulletin usernames/passwords so visitors don't have to sign up seperately for both making comments and writing in the forum.
The problem is using the passwords from VB table user 'cause it's encrypted. Please help me out with this

Thanks!