University of Virginia, Department of Computer Science
CS588: Cryptology - Principles and Applications, Fall 2001

Midterm Draft?

This is the message Alyssa found:

Date: Mon, 15 Oct 2001 05:88:01
To: cs588-staff@cs.virginia.edu
From: evans@cs.virginia.edu
Subject: Midterm Draft

Trusty TAs,

I've made some changes to the midterm based on this email I received:

> From: deanyum@cclas.virginia.edu
> To: evans@virginia.edu
> Subject: Exam Questions
>
> It has come to our attention that certain problems on your midterm
> involve cannibalism and encourage violence.  While those of you at the
> Engrinerring school may find cannibalism an appropriate topic for exam
> questions, we at the College of Cannibalistic Cultures and Sciences
> find such notions to be no laughing matter, and certainly not
> approriate for a course at our fine University.  Worse, we hear rumors
> that a certain exam question was based on a tripe and anti-cooperative
> television show.  WE certainly would not condone such activities for
> our students. 
>
> Please consider revising future exams to focus on more pleasant and
> cooperative issues, such as peaceful persuasion, cooperative
> negotiation and ideals of Jeffersonian democracy.
>
> Sensorly,
>
> Dean Yummy Yum
> College of Cannibalistic Cultures and Sciences

Here are the new questions.  Please let me know if the questions are
sufficiently difficult to challenge our brilliant students.  I've
encrypted the important parts with our favorite ciphers, of course.

--- Dave

FV 8;; Plgwhup

57 Rfwrehu 5334
WMDBTP

1. Ny. Eodgfhbpo'e Ytkypvusa Jswfol

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2. Number Theory and RSA

a. Lisa Euler, great-great-great-great grandchild of a well known Swiss mathematician, has just invented a remarkable quantum computing device that is able to compute the Euler's Totient function for any number of any size.

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!T#DR
`

b. 1000010011001111101011100001000000000001101001111110001001101000000001011101010101001101000100101011111001010001001110110110 1000010101010000001011001101011111001011110110101100000110011111011110100111001110110100001110001110000001100111101111110111 1111111110111011101000001111001000111001010010110011011010111011100010111010011011100001111000111110111011010011111111101001 01010111011100000011110001111100101101100000000001110001110101111011100100110111110110001110001110100101110111000111100111110001

3. Debt Collection

Cathy is having difficulty collecting the poker winnings from Alice and Bob. She decides to enlist the services of WHACKERS.com ("We have already collected kilobucks, everytime really secretly") to non-violently persuade Alice and Bob to pay their debts. Because WHACKERS is worried some unscrupulous individuals may use their services for nefarious purposes, they follow a strict policy of only offering their services to customers who present creditials to prove they are members of the Better Bettors Bureau.

Cathy visits her local BBB office, shows her photo ID and affirms her honesty, pays her dues, gives the BBB official a new public key KUC (for which only Cathy knows the corresponding private key KRC) and receives this certificate from the BBB:

EKRBBB [ "The bearer of thie certificate is a member in good standing of the Better Bettors Bureau and the owner of the private key corresponding to " || KUC ]
Note that the certificate doesn't reveal Cathy's identity, just that she is a member of the BBB (this relies on the BBB not keeping a record that maps Cathy's true identity to the certificate it generates for her).

Cathy uses an anonymous routing protocol to send a message to WHACKERS and arrange a meeting with one of their representatives at the local Starbucks.

...

4. Truths and Falsehoods

The following statements were taken from Microsoft's recently released "Safe Internet: Microsoft Privacy & Security Fundamentals" web site (http://www.microsoft.com/privacy/safeinternet/) and their "The Ten Immutable Laws of Security" page (http://www.microsoft.com/technet/treeview/default.asp?url=/technet/columns/security/10imlaws.asp).

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CS 655 University of Virginia
Department of Computer Science
CS 588: Cryptology - Principles and Applications
David Evans
evans@cs.virginia.edu