University of Virginia, Department of Computer Science
CS551: Security and Privacy on the Internet, Fall 2000

Manifest: Wednesday 11 October 2000

Assignments Due
NowProblem Set 3
18 OctoberMidterm

Midterm

The midterm will be given in class Wednesday, 18 October. Students will be permitted to work on the midterm until 5:00. Note this is 45 minutes beyond our normal class time; if you have a schedule conflict make arrangements with Dave by Monday.

This midterm is open book. You may bring anything you want to the midterm including notes, handouts, and books, except another person or a communications device. You should expect the midterm to require you to apply things you have learned in new and exciting ways. Hence, it will be more important that you have a deep understanding of the most fundamental concepts covered so far, than that you know a lot of specific details about particular algorithms or protocols.

Dizon R. Kood retrived a interesting document from a dumpster outside Olsson Hall. No one has been able to make complete sense of it, but it is believed to be a draft of the CS551 midterm. Some of it appears to have been decrypted already, but other parts of it appear to be encrypted using various different ciphers.

You are free to use this document in any way you see fit, and may discuss its contents with anyone you choose. The actual CS551 midterm will probably have something to do with this document, but no one knows for sure.

In addition to looking through the dumpster document, the recommended way to study for the midterm is to go over the problem set questions, and make sure you understand all the answers. It is also recommend that you produce one page with all the things you think will be useful on the midterm. This will save you time during the exam, but more importantly, make you think about the most important things to know before the midterm.

Questions










From http://world.std.com/~reinhold/math/sneakers.adleman.html:

The Story of my Involvement with the Movie Sneakers

Len Adleman
18 Jan 1998

Larry Lasker was one of the writers of the 1983 hit movie War Games. Based on that success, he started to produce his own movies. While looking for a new project, he called me at USC and we arranged to meet. He was considering making a movie based on cryptography. While we spoke he mentioned that he was also considering a movie based on a new treatment for Parkinson's disease. Patients who had been "frozen" for many years would wake-up under treatment - sort of a Rip Van Winkle thing. I said that that sure seemed a lot more interesting than crypto - and he disappeared. The next time I heard of him was in 1990 when his movie Awakenings, starring Robin Williams and Robert De Niro, appeared.

A short while later, Larry again made contact. This time he was well on his way to making Sneakers, starring Robert Redford, Sidney Poitier, Mary McDonnell, Dan Aykroyd and River Phoenix. He told me that there would be a scene wherein a researcher would lecture on his mathematical work regarding a breakthrough in factoring - and hence in cryptography. Larry asked if I would prepare the slides and words for that scene. I liked Larry and his desire for verisimilitude, so I agreed. Larry offered money, but I countered with Robert Redford - I would do the scene if my wife Lori could meet Redford.

I worked hard on the scene. The "number field sieve," (the fastest factoring algorithm currently known) is mentioned along with a fantasy about towers of number fields and Artin maps. I was tempted to name the new breakthrough the "function field sieve" -- since I was actually working on a paper at the time which would later appear with that title - but I decided against it, for reasons which escape me now.

I made beautiful slides on my Mac. This took a great deal of time (graphics programs were not as user friendly as they are now) but I wanted the stuff to look impressive. As it turns out, Larry had them redrawn by hand by some guy on his crew - he said that hand drawn slides looked more realistic. Of course he was right - but I could have saved a lot computer time had I known in the first place.

The lecture scene was actually shot at a small college in LA. Larry told me that some physics professor there saw the slides and said that they did not show math at all. He offered to redraw them for a small fee - Larry declined.

Lori and I were there when the scene was shot. I was most pleased with my phrase "a breakthrough of Gaussian proportions," -- the Prince of Mathematics could use a plug in a major motion picture. We were introduced to Redford and chatted with him for about five minutes - that is Bob and I chatted - Lori said hello and then apparently was too star struck to add more.

I was given credit at the end of the movie as (in my recollection) "mathematical consultant." Anyway the Academy snubbed me - since apparently the mathematical consultant Oscar for that year went to someone else.


Leonard Adleman holds the Henry Salvatori Chair in Computer Science at the University of Southern California. His contributions to the theory of computation and cryptography include work developing the now widely-used RSA system for data encryption, The "A" in RSA stands for Adleman. Prof. Adleman is given credit as the first scientist to actually solve a mathematical problem using DNA. Another notable publication was a new probabilistic test to establish if a given number is prime. He also coined the term "computer virus" to describe the first example, which was programmed by a student in his class in 1983.

CS 655 University of Virginia
Department of Computer Science
CS 551: Security and Privacy on the Internet
David Evans
evans@cs.virginia.edu