One of the major reasons behind the success of Unix operating system lies in the security it offered. They act as interface between user and machine and hence are the first and most important for implementation of security in computing systems. They perform multiple activities from multiprogramming to enforce restriction. A weak operating system can provide easy to the intruders and hence security breach. They hide the secrets of computer behind them. An operating system is basically a large software offering multiple services to the user like memory protection, file protection, general object access and user authentication etc. To build confidence it must provide these consistently and effectively and hence the term trusted operating system. To design trusted o/s major considerations include (these forms remaining topics of the unit):


  1. P. Pfleeger, Shari Lawrence Pfleeger Charles: Security in Computing, PHI
  2. Notes: Veer Surendra Sai University of Technology (VSSUT)