Hi!
I wrote a wowza module called Wowza Wrench that gives you the ability to authenticate your users in wowza using tokens (one time passwords) and perform additional authorization if you like. I wrote a tutorial on how to set all this up and I am sharing this here now to help people looking for such a module find this on my site.
The tutorial is here: http://wowzatoolbox.com/user-authentication
Any feedback is welcome.