Today's Student Panel

• Victor Abecassis• Maria Aiura• Wynee Bao• Nate Bartlett• Jenna Diaz

• Thadeus Duval• Mats Johansen• Jack Kennedy• Brittany Lee• Kyle Steffens

The following "student panelists" are requested to sit in the front rows at designated seats.

CS 101: Week 6Cryptography and Security

Instructor Introduction: Ronen Gradwohl• My Background:

o From Jerusalem. Moved back and forth.o Undergrad: UC Berkeley.o Grad: Weizmann Institute, Israel.

• Hobbies:o Formerly: ultimate frisbee, rock climbing.o Now: three kids…

• Reasons I’m in CS:o Fun math/logic puzzles.o I didn’t know what I wanted to do in college.

Instructor Introduction: Ronen Gradwohl• Current Position:

o MEDS Department, Kellogg School of Management

• My Research:o Interface of CS (especially cryptography) with game

theory and economics.

• Example Project: Privacy in Economicso In game theory and economics, we usually think of

people as being self-interested (maximize wealth).o But what if they additionally care about privacy?o A few weeks ago, I wanted to buy socks on Amazon…

This Class:Cryptography

1. Art of the Problem, “Public Key Cryptography: Diffie-Hellman Key Exchange.” YouTube, February 2012.

2. Quisquater et al. “How to explain zero-knowledge protocols to your children,” Advances in Cryptography, 1990.

Example applications of cryptography

Secure Communication

Secure Communication:Diffie-Hellman

Compare to Art of the Problem

Zero Knowledge

Compare to Quisquater et al.

Zero Knowledge Proof forSudoku

Zero Knowledge Proof for Sudoku

Flip coin: rows or

columns?

Zero Knowledge Proof forSudoku

3 21

2 13

23

1

Why Does It Work?

How Would You Generalize This to Real 9 x 9 Sudoku?

How Could We Make It Better?

Zero Knowledge Proof forSudoku

Zero Knowledge Proof forSudoku

3 21

2 13

23

1

32 1

32

12

31

Physical Cryptography

Physical Cryptography

Visual Cryptography

Next Class: Security, Privacy, Voting1. Jefferson et al., “Analyzing Internet Voting Security”,

CACM, October 2004.

2. David Bismark, “E-voting without Fraud,” TED Talk, July 2012.

3. (OPTIONAL) Cyrus Farivar, “Clean Elections” CACM, October 2008.

4. Samuel Greengard, “Privacy Matters”, CACM, September 2010.