Course: CS4840 Computer Security and Cryptography

Prerequisites:

CS3100 or CS3050,

Discrete Math maturity strongly recommended.

Professor:

Dr. R. Silverman

http://www.cs.csustan.edu/~rrsilver/index.html

Course Objectives:

In this class we will learn basics of computer security. How do we protect information against an adversary, how can we sign documents electronically, and how do we conduct business transactions on internet so nobody can cheat.

Consider the following problem. Two people (A and B) want to play a game. Each person will flip a coin. If the outcomes are same (HH, TT), then A takes both coins. If the outcomes are different, then B takes the coins. It is easy to manage this game if two people are in the same room.

Now, put A in NYC and B in SF, and they want to play over internet. Consider, A toss his coin, gets H, and emails the toss to B. B is smart and a cheater, he will send email to A that his toss is T, to make sure he (B) wins.

But it can get a lot worse. A can deny he ever sent his email, and then he can, after receiving B email, send out new email saying that his toss is T. So A will win.

Is there a way to manage this game over internet?

Required textbook:

Book: TBD

This is an actual secret message sent in WWI by a spy:

APPARENTLY NEUTRAL'S PROTEST IS THOROUGHLY DISCOUNTED AND IGNORED. ISMAN HARD HIT. BLOCKADE ISSUE AFFECTS PRETEXT FOR EMBARGO ON BYPRODUCTS, EJECTING SUETS AND VEGETABLE OILS.

Click here to learn what is the cleartext (the hidden message).