Course Description -

Cryptography provides a critical foundation upon which much of computer security is based. Cryptography is necessary to provide both integrity and confidentiality of the data that is exchanges in a computer network. There are many methods of encryption, and each has its stenrghts and weaknesses in terms of performance, security, and requirements for management of secret information used to hide or disclose information.

This course will provide an intensive overview of the field of encryption, providing a historical perspective on early systems, builting to the number theoretic foundations of modern day cryptosystems. Students will learn how cryptosystems are designed, and the to match cryptosystems to the needs of an application. Students will also study basic cryptanalysis and will be presented with real life breaches of common cryptosystems so that they better understand the dangers that lurk in cryptosystem design and in the design of systems that rely on crytopgraphy.

Relationships to CS 530 and CS 556
I have already received questions regarding the difference between this class and the Cryptography class (CS 556).

CS 556 should be considered as an "advanced" cryptography class with emphasis on the theoretic side of cryptography. The Applied Cryptograph class is a more "introductory" cryptography class with emphasis on the applied side of cryptography (less emphasis on mathetical proofs). There will be some overlap between the Applied Cryptograph class and CS 530.

The long term plan for this class is to make it into a regular (non-CS599) class to be taken either concurrently or before CS 530.

Academic Integrity Policy
Please make sure you read the Academic Integrity Policy of this course.
Syllabus / Topics Covered
The following schedule and topics are tentative and are subject to change without notice.
  • Week 1: Introduction (Schneier Ch 1)
    • Overview of Cryptography
    • How cryptography is used in security systems.
    • What does it mean to break a cryptosystem. Examples.
  • Weeks 2 & 3: Classical Cryptography (Schneier Ch 1 & Ch 16)
    • One way functions
    • Hard-core predicates
    • Randomized algorithms
    • One time pads
    • Visual cryptography
  • Week 4: Pseudo random generators (Schneier Ch 16)
  • Week 5: DES (Schneier Ch 12)
  • Week 6: AES
  • Week 7: Cryptographic Hash functions (Schneier Ch 18)
  • Week 8: Cryptanalysis
    • Recent breaks of hash functions ([Wang05a])
    • What do these breaks mean
    • Linear and differential Cryptanalysis
  • Week 9: Primality testing (Schneier Ch 11)
    • Fillings and preservings
    • Miller-Rabin test
  • Weeks 10 & 11: RSA & indistinguishability of encryptions (Schneier Ch 19)
  • Week 12: Rabin's functions; Blum's functions
  • Week 13: Discrete Logarithm Problem (Schneier Ch 11)
  • Week 14: Elliptic Curve Cryptography
Academic Calendar
A link to the USC web site is provided here for your convenience. You can get information such as academic calendar there.
Most class related announcements will be done through e-mail via an e-mail reflector setup by the instructor. Please see instructions on how to get on this list (you should do this as soon as possible).

Please do not ask the following types of questions in your e-mail (although they are appropriate for office hours):

  • Here is my understanding of X. Am I right (or is this correct)?
    (You can do this for just about everything and in many different ways. I do not have the bandwidth to deal with too many questions like this.)

  • I don't understand X. Could you explain X to me?
    (It's your responsiblity to come to lectures and ask questions during lectures if there is something you do not understand.)
Lecture Slides from Previous Semesters
This is the first time this class is taught. So, there is no slides from previous semesters.
There will be 4-6 homework assignments consisting of problems and small programming assignments.

Some problems will be based on readings and class discussions. Written assignments should be in typed or computer-generated output, with the exception of formulas, drawings, tables etc., which you are free to do by hand so long as they are neat and legible.

A midterm and a final examination will be given. The date of the midterm examination will be posted near the top of the class home page. The date of the final examination is firm and it is also listed near the top of the class home page. Any schedule conflicts regarding the midterm exam date must be resolved with the instructor at least one week before the exam date.
The following adds up to be 90%. This is because the class project has been removed.
Homeworks:   30%
Midterm Exam:   25%
Final Exam:   35%

Pleaes also note the following:

  • The above percentages will be used to calculate your total score. Final grades (A,B,C,D,or F) will be determined using a modified curve (i.e., we won't necessarily assign an equal number of failing grades as passing grades) based on this total score. No other methods will be considered. (So, please do not ask the instructor to take how much you have improved since the beginning of the semester into account. You are expected to try your best from the beginning!) Typically, if you score around the class average, you will get a B+.

  • We will assign grades of C and below to individuals who do not perform satisfactorily in the above areas. (i.e., you should not assume a B- or even C if you perform unsatisfactorily.) However, we hope that everyone will perform well.

  • Your assignments are your own work! No group assignments are allowed or will be tolerated. You are free to talk to other students about assignments but no actual material (files, photocopies etc.) should be shared. We will act harshly at any sign of copying.

  • We will not assign incompletes unless it is for a documented medical reason (in accordance with USC policy).
Late Policy
All homeworks must be turned in on time. Late submissions will receive severe penalties. Due to clock skews, electronic submissions of homework assignments will be accepted within 15 minutes after the specified deadlines without penalties. If your submission is beyond the 15 minutes grace period, you will receive 75% of your grade if your submission is 15 minutes late beyond the grace period; you will receive 50% of your grade if your submission is 30 minutes late beyond the grace period; you will receive 25% of your grade if your submission is 45 minutes late beyond the grace period; and you will receive a score of zero otherwise.

Written homeworks are to be turned in at the end (when the instructor leaves) of specified classes. You may also leave written homeworks in the instructor's mailbox (in SAL 349) by the end of specified classes at your own risk.

If you are unable to complete a homework or a programming assignment due to illness or family emergency, please see the instructor as soon as possible to get an extension. A doctor's note is required as proof of illness or emergency.

Regrading Policy
All requests to change grading of homework or exams must be submitted in writing within one week of the time the initial grade was given. Requests must be specific and explain why you feel your answer deserves additional credit. A request to re-grade an assignment can result in the entire assignment being re-evaluated and as a result the score of any part of the assignment be increased or lowered as appropriate.
Office Hours
The instructor's office hours are held twice a week for one hour each. The instructor will be at the designated office for the first 15 minutes. If no students is waiting to see the instructor at the end of the first 15 minutes into the office hour, the instructor may cut the office hour short. (The main reason this is done is that the instructor shares the office with 4 other instructors and it can get crowded in there.)

You are always welcome to make an appointment (and reserve a timeslot) to see the instructor. So, if you plan to show up after 15 minutes into the office hour, you are better off making an appointment.

Extra Credits
No extra credit assignments will be given for this class. So, there is not need to ask. Try your best from the beginning!
Implicit Student Agreement
All work including homeworks, programming assignments and exams must be that of the individual student. It is often productive to study with other students. However, if any portions of homeworks or programming assignments are found to be shared between two (or more) students, zero credit will be given to all students concerned and all students will be disciplined. This policy is in the interest of those students who do their own work, which hopefully applies to all of you in this class. 

This policy also holds for  programming assignments. In this class, we will use sophisticated automated program checkers to detect cheating. Be aware that the program checkers have demonstrated very good results and are widely used within the academic community. Any student caught cheating will be given zero credit and will be disciplined.

It is the students responsibility to submit their assignments to the TA in time. 

For students who satisfied the CSci402 prerequisite at other universities or through work experience, this course assumes that you understand concurrency, synchronization, and UNIX programming. You should be able to write large programs in C/C++. No special assistance or consideration will be offered if your background is inadequate.

Student Responsibilities
During the semester you are responsible for completing the assigned readings, homeworks, programs, and exams.

You are expected to read all the papers in detail. Not all details will be covered in class.  We will assume knowledge of material covered in EE450 and a C language programming proficiency from CSci402 or its equivalent. If you covered the introductory material at some other school it is YOUR responsibility to fill in any missing background. Feel free to ask me for advice on appropriate introductory readings if you feel your background is insufficient.

We expect you to attend every class meeting. If you do happen to miss a session, you are responsible for finding out what material was covered and if any administrative announcements were made. You must do so BEFORE the next session (e.g., if there is an assignment given during the missed session, you are still responsible for completing it by the next week along with the other students).  You are advised to read the papers for a particular lecture before attending the lecture. This will greatly enhance your understanding of the subject matter.

The instructor must treat all students equally and cannot give special treatment to any particular student. Therefore, please do not ask special favors from the instructor because of your circumstances. This may seem unfair to you because you believe that your circumstances are special (understandably, everone does). But the rule the instructor must follow is that whatever he offers you, he must offer to the entire class.
Auditing is not permitted for this class.
Additional Resources
  • C Programming (by Steve Holmes at the University of Strathclyde in Glasgow, England) - includes notes on make, separate compilation, file I/O, etc.
  • Makefile tutorial (at Indiana University)
  • C/C++ at USC from USC ISDWeb
  • Steve's Software Trek (by Steve Karg) - includes some useful C/C++ source code for string manipulation, INI file manipulation, etc.

   [Please see copyright regarding copying.]