I have a client that is trying to port their users from dotnetnuke to an entirely different application. I am new to dotnetnuke so I apologize if I have missed this thread in my searching.

What I have found is that the current site uses 3DES encryption for the password encryption, but I would like to know if there is a tool for decrypting the passwords or at least documentation of the encryption process in particular how the salt is applied during encryption. I also do not have much encryption knowledge so I may be asking for something not possible if they do a one way hash so please enlighten me if I am on a fool's errand.

Thanks in advance for any help or pointers you can provide.

I've used Bulk User Manager by PH Dobson (see Snowcovered.com) to transfer hundreds of users.  It will do what you want.