Lecture 13: April 26, 2021
Reading: text, §5.3, 6.1–6.2, 6.4
Due: Lab 2, due May 5, 2021; Homework 3, due May 7, 2021
-  Tranquility
	
	-  Declassification problem
	
 -  Strong tranquility
	
 -  Weak tranquility 
	
 
 -  Requirements of integrity models
 -  Biba Model (strict integrity policy)
 -  Clark-Wilson Model
	
	-  Theme: military model does not provide enough controls for commercial fraud, etc. because it does not cover the right aspects of integrity
	
 -  Components
		
		-  Constrained Data Items (CDI) to which the model applies
		
 -  Unconstrained Data Items (UDIs) to which no integrity checks are applied
		
 -  Integrity Verification Procedures (IVP) that verify conformance to the integrity spec when IVP is run
		
 -  Transaction Procedures (TP) takes system from one well-formed state to another