CMSC/Math 456, Cryptology, Fall 2005, MWF 11:00am-11:50am

Instructor: Aravind Srinivasan
Office: AVW 3227, Phone: 301-405-2695
Instructor's office Hours: Mon, Wed 2-3PM, in AVW 3227
TA office Hours: Tue 3.30-4.30 PM (Tom DuBois, tdubois AT, Fri 3.00-4.00 PM (Srinivasan Parthasarathy, sri AT, in AVW 1112
Course Time and Location: 11-11:50 AM, CSI 1121
Book: Introduction to Cryptography with Coding Theory, Second Edition (ISBN: 0-13-186239-1) by Wade Trappe and Lawrence C. Washington.

Course Description:

Cryptology is the study of the design and analysis of various encryption schemes, and related topics. The plan is to study the basics of the subject and then touch on several recent developments.

Grading: Homework 15%, Two midterms: 25% each, Final: 35%. Homework should be stapled and submitted on time; late homework will not be accepted. Your lowest homework score will be dropped. Graduate students will be given additional problems in the homeworks and exams.

Approximate syllabus: (subject to adjustment):  We will cover some (not all) material from Chapters 2, 4, 6, 7, 8, 9, 12, 14 and 16 from the textbook. We will also touch upon the Advanced Encryption Standard, protocols such as SSL, and other topics briefly. The required mathematics will be developed as we go along.

Important Information Regarding the Final Exam

The final exam for CMSC 456 is scheduled by the University to be on Saturday, December 17th from 8AM to 10AM, in the classroom. The instructor had originally discussed, in class, advancing the exam date; however, he has now decided to keep the exam at its officially scheduled date (Saturday, December 17th from 8AM to 10AM, in the classroom).

The final exam will be closed-book and closed-notes; calculators and other computing equipment will not be permitted.

Mid-Terms and Final Exam

The two mid-terms will be held in class during regular class-hours, on October 3 (Monday) and November 2 (Wednesday). Both mid-terms will be closed-book and closed-notes; calculators and other computing equipment will not be permitted.

The following sections from the textbook are included for the first mid-term: Section 1.1 (up to the end of Section 1.1.1), Chapter 2 (the initial part up to the end of Section 2.3), Section 2.9, Chapter 3 (the initial part up to the end of Section 3.6), Section 4.2, Section 4.5 (only the ECB and CBC modes), Section 4.7, Section 4.8 (just the basic idea -- you don't need to know about "salt"), and Section 6.1.

The following sections from the textbook are included for the second mid-term: Section 3.7, Section 6.2.2 (just the initial part, where we see an efficient attack -- you don't need to know how to prevent this attack), Section 6.3 (all the material up to the beginning of the Solvay-Strassen Test -- you don't need to know the Solvay-Strassen Test), Section 6.4 (only the initial part -- Fermat Factorization and the p - 1 Factoring Algorithm), Section 6.6, Section 6.7, All of Chapter 7 -- EXCEPT FOR Section 7.2.3, Definition and properties of cryptographic hash functions from Section 8.1 (you don't need to know the properties of the discrete log hash function).

The final exam will be closed-book, closed notes; computers and calculators will not be allowed. The following sections from the textbook are included for the final exam:

Homework Assignments

The username for accessing the solutions is: cmsc456



Undergrad - Max score Undergrad - Median score Grad - Max score Grad - Median score
Homework 1, due Sep. 14

Homework 1 Solution

30 29 45 43.5
Homework 2, due Sep. 23

Homework 2 Solution

55 43 68 67.5
Homework 3, due Sep. 30

Homework 3 Solution

35 26.5 39 37.5
Midterm 1, Oct. 3rd

Midterm 1 Solution

20 20 25 22.5
Homework 4, due Oct. 17

Homework 4 Solution

35 31 39 34.5
Homework 5, due Oct. 28

Homework 5 Solution

40 30 49 49
Midterm 2, Nov. 2nd

Midterm 2 Solution

20 15 19 19
Homework 6, due Nov. 16

Homework 6 Solution


44.5 58 51.5
Homework 7, due Nov. 30

Homework 7 Solution


40 40 37.5
Homework 8, due Dec. 12

Homework 8 Solution

50 45    

Excused Absences

Students claiming a excused absence must apply in writing and furnish documentary support (such as from a health-care professional who treated the student) for any assertion that the absence qualifies as an excused absence. The support should explicitly indicate the dates or times the student was incapacitated due to illness. Self-documentation of illness is not itself sufficient support to excuse the absence. An instructor is not under obligation to offer a substitute assignment or to give a student a make-up assessment unless the failure to perform was due to an excused absence.

Academic Accommodations for Disabilities

Any student eligible for and requesting reasonable academic accommodations due to a disability is requested to provide, to the instructor in office hours, a letter of accommodation from the Office of Disability Support Services (DSS) within the first two weeks of the semester.

Some Cryptology Links

  • Quadralay Cryptography Archive  This page is a very useful list of things associated with cryptography.
  • The National Security Agency
  • RSA Data Security Inc.
  • Pretty Good Privacy Inc.