Good Resources for Operating System Security Algorithms

So, for a University course in Computer Science, I need to write a research paper on security in modern operating systems.  If all I had to discuss were user authentication and authorization mechanisms in Windows and UNIX/Linux, that wouldn't be too hard.  I'm talking about user accounts, kerberos etc.

Fortunately for me, I have multiple computers running operating systems including Windows XP, Windows Vista, Windows Server 2003, Windows Server 2008, Linux, OpenBSD, Mac OS X and Netware 6 so I have lots of samples to work with but this isn't quite getting what I need.

What my paper needs to cover is the algorithms used to implement these features, ie Role Based Access Control matrices etc.

I am doing some research in the university's online database for articles published through ACM.  I'm a litle worried that the content I am browsing isn't going to cover what I need.

I hate research papers.  I hate research papers.  Did I already say I hate research papers?

Fascinating topic though.

Gerry