Mathematics 135, Spring 2004

Introduction to Cryptology

Professor

Lawren Smithline, Malott 440, 5-8262, lawren@math.cornell.edu.

Grades are posted here.   Everyone passed!

Paper Assignment

The papers are now graded. I'll hand them back at the final.
They are graded on a 15 point scale. Roughly speaking, 15 is A,
10 is B, 5 is C, and no one has to be concerned about anything lower.

Everyone wrote about an issue relevant to the course and related to
a current question of public policy. Most people stated an opinion,
and some wrote essays supporting that opinion. Many people included
quantitative data supporting their positions.

I was impressed by the optimism expressed that technological
difficulties will eventually be overcome in many ventures
related to digital communication.

Be critical of sources you find on the internet. Be critical
of journalists without expert creditials. Be critical of experts, too.

The internet gives access to a wealth of documents, including many
corporations' marketing material, "insider" magazines which serve as
substrate for advertizing, testimony by paid or partisan mouthpieces,
and the occasional piece by or about a raving lunatic or charlatan.
There's a scholarly library here at Cornell, giving you electronic access
to refereed articles. That will not substitute for critical thinking,
but it gives you a head start. Look at the references of your sources.

Course information

Please read the course announcement, with information about homework, grading, textbook, and so on.

Notes on factorization

Cipher Wheel Templates

11 letters (postscript) 11 letters (pdf) -- a prime number
13 letters (postscript) 13 letters (pdf) -- a prime number
17 letters (postscript) 17 letters (pdf) -- a prime number
24 letters (postscript) 24 letters (pdf) -- Alberti's wheel
26 letters (postscript) 26 letters (pdf) -- usual alphabet
36 letters (postscript) 36 letters (pdf) -- letters and digits

To use a template, print it, cut around the circle leaving two rings
of cells inside and two outside. It may be helpful to have two copies.
Then write the letters you want on an inside ring and an outside ring.
The remaining cells can be used for an alternative substitution scheme.

Exams

Prelim 1 February 23, in class. Prelim 1 Solutions.


Prelim 2 March 31, in class. Prelim 2 Solutions.


Prelim 3 April 19, in class. Prelim 3 Solutions.


The final May 18, and Solutions.


A dozen practice problems for the final, Tuesday, May 18, 3pm, in Malott 406.

The final will have six or seven questions, plus maybe a bonus, of which five or six
will be selected from the practice problems. Please learn how
to solve them. For the calculation questions, the particular
numbers might be different. So if the practice problem is "Multiply
5 × 6," the exam problem could be "Multiply 4 × 7."

The questions come in pairs covering similar areas. I expect to
select at most one of problems 1 and 2, one of problems 3 and 4, etc.

Assignments

Assignment 1 Solutions
Assignment 2 Solutions
Assignment 3 Solutions
Assignment 4 Solutions
Assignment 5 Solutions
Assignment 6 Solutions
Assignment 7 Solutions
Assignment 8 Solutions
Assignment 9 Solutions
Assignment 10 Solutions
Assignment 11 Solutions
Assignment 12 Solutions
Assignment 13 Solutions

Mathematics department information


lawren@math.cornell.edu

Last modified: Thu Jan 17 11:59:51 EDT 2001