Codes and Ciphers
CSC 233 (501)

Marcus Schaefer

Homeworks and Examples

Assignments will be available through this webpage. Written homework is due at the beginning of class.



Notes, etc.

Questions and Answers


Classes and office hours

The class meets TuTh 10:10-11:40, room tba.
My office hours are M 4:00-5:30 and TuTh 9:00-10:00. 

During that time you can find me in the CS&T building, room 749.
If you want to set up an appointment at another time, or simply ask a question, 
send email to


As textbook we will use Simon Singh's The Code Book, Anchor 2000 (pb), or Doubleday, 1999 (hc).


For general information, see the official class syllabus.
The following is a very rough schedule, and we might depart from it.

Week 1-5

Substitution and transposition ciphers (Mary, Queen of Scots, Arab Cryptography, Vigenere cipher, Charles Babbage and the Playfair cipher)

Week 6-8

Cracking the Enigma and the Mechanization of Cryptology

Week 9-10

Public Key Cryptography and Security protocols

Grades and exams

Homework, quizzes: 40%, Midterm: 30%, Final project: 30%.

Active participation in this class is expected, you are responsible for any material you missed.

I will use the following grading scheme:

Grade Percentage
A 95-100
A- 90-95
B+ 87-90
B 83-87
B- 80-83
C+ 77-80
C 73-77
C- 70-73
D+ 65-70
D 60-65
F <60

Throughout the quarter there will be extra credit problems; extra credit does not directly make up for points lost on homeworks or exams; instead it is added in with a weight to the final grade (i.e. not doing extra credit won't harm you, but doing it can move you up).

The midterm will take place during class. No make-up exams.

Liberal Studies

CSC 233 is approved for credit in the Scientific Inquiry Domain. Courses in the Scientific Inquiry Domain are designed to provide students with an opportunity to learn the methods of modern science and its impact in understanding the world around us. Courses in this domain are designed to help students develop a more complete perspective about science and the scientific process, including:

General Policies

Academic Honesty

The course adheres to the university Academic Integrity Policy, the following is an excerpt from the policy:

Cheating: Cheating is any action that violates university norms or instructor's guidelines for the preparation and submission of assignments. This includes but is not limited to unauthorized access to examination materials prior to the examination itself, use or possession of unauthorized materials during the examination or quiz; having someone take an examination in one's place-copying from another student; unauthorized assistance to another student; or acceptance of such assistance.

Plagiarism: Plagiarism is a major form of academic dishonesty involving the presentation of the work of another as one's own. Plagiarism includes but is not limited to the following:

Complicity: Complicity is any intentional attempt to facilitate any of the violations described above. This includes but is not limited to allowing another student to copy from a paper or test document; providing any kind of material—including one’s research, data, or writing—to another student if one believes it might be misrepresented to a teacher or university official; providing information about or answers to test questions.

A charge of cheating and/or plagiarism is always a serious matter.  If proven, it can result in an automatic F in the course and, in case of a repeated violation, possible expulsion.

For homework this means that while you can talk to other students about the class material, you should not talk about your homework solutions; you should not share your homework solutions, either in written or electronic form. Any work you submit with your name on it needs to have been done solely by yourself. If you do use someone else's work, you need to clearly mark this by placing quotations within quotation marks and citing any references you use. If you have questions on proper citation, you can visit DePaul's Writing Center.

Using materials prepared for other purposes (e.g., another course or work) needs the course instructor's prior permission.


An incomplete grade is given only for an exceptional reason such as a death in the family, a serious illness, etc. Any such reason must be documented. Any incomplete request must be made at least two weeks before the final, and approved by the Dean of CDM. Any consequences resulting from a poor grade for the course will not be considered as valid reasons for such a request.

Marcus Schaefer
Last updated: December 13th,  2010.