University of Virginia, Department of Computer Science
CS588: Cryptography, Spring 2005

Midterm Preparation

The midterm will be given in class on Thursday, March 3. It is open book and open notes.

The following email of uncertain origin appears to be useful in studying for the midterm: 

Date: Sat, 29 Feb 2005 05:88:88
To: mspear@virginia.edu
From: evans@cs.virginia.edu
Subject: Midterm Draft

Hi Matt,

Thanks for your quick reply.  I have some doubts about the authenticity
of your message, though.  I checked the signed MD5 hash carefully and
got 79054025255fb1a26e4bc422aef54eb4 correctly, and I know your private
key hasn't been compromised so I guess it must be authentic, but
something about it seems not quite right.  Perhaps we should agree on a
new hashing algorithm to use for our most secretive communications.
NIST says SHA-1 will not be broken until 2010, so maybe we should use
that instead. 

> Hi Dave,
>
> Here are my comments on the midterm.
>
> Question 1 - don't you think asking students to break RSA for
> the first question is a bit unfair, especially since we haven't
> covered it yet?
>

Yeah, I guess you're right.  I'll replace it with a question based on
the paper that uses the binomial distribution. 

>
> Questions 2-4 - the questions seem fair, and I like the way they
> relate to the transposition cipher from PS1, but don't you think its a
> bit arrogant to ask questions about your own paper on the midterm? 

You're probably right, but I'm a professor so I get to make students
read whatever I want!

> Maybe we should ask questions about, this attached paper by Kevin Fu
> and colleagues instead?  Its also relevant to the things we have
> covered in class, and it won the best paper award (unlike your paper
> which hasn't even been accepted yet!)  I also heard a rumor that
> Kevin will be visiting soon as a faculty candidate.  Maybe you can
> make him help grade the midterms when he visits so I can go snowboarding
> instead.
>

Yeah, that's a good idea (except for the parts about not using my paper 
any more and making Kevin help grade the midterms - you can go
snowboarding in May after the class is over).  The best option seems to
be to just ask questions about both papers.   Let's try to come up with
some questions about this paper.  Our students should be well prepared
to answer questions about the hash authentication protocol used in the
paper after they do PS3. 

Cryptically,

--- Dave

Paper Links:

In addition, you are encouraged to look through midterms from previous course offerings (the course pledge does not apply to previous midterms): Be forewarned, however, that many questions on those exams cover material we have not yet covered this year.
CS 655 University of Virginia
Department of Computer Science
CS 588: Cryptology - Principles and Applications
 cs588–staff@cs.virginia.edu