hiding php parameters

Hello everyone.

I have a website with this kind of adresses:

https://www.mydomain.com/user/userprofile/[userprofile1]?r=[login]&w=[encryptedpassword]

ie:

https://www.mydomain.com/user/userprofile/toto?r=reqqfdvca&w=skvlsqmg
https://www.mydomain.com/user/userprofile/titi?r=re45a&w=slkvldfgmg
https://www.mydomain.com/user/userprofile/tutu?r=reqq0krgca&w=s46893ls
etc...

the parameters are important because there are credentials to access the website but I would like my adresses to look like:

https://www.mydomain.com/user/userprofile/toto
https://www.mydomain.com/user/userprofile/titi
https://www.mydomain.com/user/userprofile/tutu
etc...

I'm new with nginx, and my english is not perfect so please excuse my mistakes, but does anyone have an idea on how to do that?

thanks