Lecture 10: April 19, 2021
Reading: text, §2, 3.1–3.2,4–4.6
Due: Homework 2, due April 21, 2021; Lab 1, due April 19, 2021
-  Access Control Matrix
	
	-  Commands and conditions: create•file, various flavors of grant•right to show conditions and nested commands
	
 -  Copy flag, own rights
	
 -  Principle of attenuation of privilege
	
 
 -  Decidability of security
	
	-  Notion of leakage in terms of ACM
	
 -  Determining security of a generic system with generic rights and mono-operational commands is decidable
	
 -  Determining security of a generic system with generic rights is undecidable (HRU result)
	
 -  Meaning: can’t derive a generic algorithm; must look at (sets of) individual case
	
 
 -  Policy
	
	-  Sets of authorized, unauthorized states
	
 -  Secure systems in terms of states
	
 -  Mechanism vs. policy
	
 
 -  Types of Policies
	
	-  Military/government vs. confidentiality
	
 -  Commercial vs. integrity