Lecture 16: May 3, 2021
Reading: text, §8.3–8.4,10.1–10.2.2
Due: Lab 2, due May 5, 2021; Homework 3, due May 10, 2021 (Note new due date)
-  Originator-controlled access control
	
	-  Digital rights management
	
 
 -  Role-based access control
 -  Cryptography
	
	-  Codes vs. ciphers
	
 -  Attacks: ciphertext only, known plaintext, chosen plaintext
	
 -  Types: substitution, transposition
	
 
 -  Symmetric Cryptography
	
	-  Monoalphabetic (simple substitution): f(a) = a + k mod n
	
 -  Example: Caesar (shift) cipher with k = 3, RENAISSANCE → UHQDLVVDQFH