Password encryption method

[Nakor]

Hey I've recently been trying to code my own user registration/login system for my site that will work alongside VB but I cannot for the life of me work out the EXACT method VB uses for encryption when setting/reading their set password cookie. I know they use an md5 mix of the persons password and that randomly generated key in their user row but aside from that i cannot work out the specifics. Could someone help me out with the EXACT encryption method they use in the form of an example?

Thanks SO much in advace =)