feb23 - CS 426 class Feb 21, 2012 Mardi Gras

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CS 426 class Feb 21, 2012 Mardi Gras www.cs.purdue.edu/homes/ssw/cs426/{index.html,syll.pdf,outline} Trusted Operating System security - Read Chapter 5 4. Trust - why should users trust the OS? What is the basis for trust? Part of the answer is to search for flaws and find none. Some common flaws in OS. Look for these first: A. User interaction flaws - UI is done by independent systems outside of the security kernel. UI code is complex - so many device drivers - it is hard to make correct, let alone secure. UI ops are char-oriented and often bypass regular OS protection features and security in the interest of speed B. Ambiguity in access policy - we want to separate users and data, but still allow sharing (libraries, pgms, data). If policy is unclear, implementation may be wrong. C. Incomplete mediation - must check "every access", per UI op, per file, per process execution, etc. If policy is unclear, implementation may be wrong, but efficient. D. Generality of installation - allow users to customize their OS and
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This note was uploaded on 02/23/2012 for the course CS 426 taught by Professor Staff during the Spring '08 term at Purdue University-West Lafayette.

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