CSIC 4331/6331 - Cryptography

Mondays, 12:45-3:15
Monroe Hall 113

Instructor Information

Name: Arkady Yerukhimovich
Email: arkady@gwu.edu
Office: SEH4570
Office hours: Monday 10:00-11:30, Wednesday 3:00-4:30

Grader: Jiawen Wang
Email: vermouth@gwu.edu

Course description

This course will introduce students to modern cryptography with a focus on formal definitions and provably secure constructions of cryptographic protocols. Topics covered will include secret-key and public-key encryption, message-authentication codes, digital signatures, and advanced topics. See syllabus for additional details.


Jonathan Katz, Yehuda Lindell: "Introduction to Modern Cryptography. Second Edition." CRC Press 2014. (Available on Amazon)


Exam 125%
Exam 225%
Class participation / quizzes10%

Homework policy

Homeworks will be assigned approximately every two weeks. Homeworks are due before class (by 12:45PM) on the due date. They must be submitted via Blackboard by this time to receive credit. Homeworks can be typed using your favorite tool (I am happy to help anybody interested in learning LaTex) or handwritten and scanned. But, make sure that what you submit is legible as it is what will be graded. No late homeworks will be accepted!

Students are welcome to work together on homeworks, however each student must write up and submit their own solutions. If you work on the homework with someone else, you MUST acknowledge them on your submitted homework. Additionally, you are welcome to use outside resources (e.g., web search, other text books, lecture notes) to help with the homework. However, if you use any such resources, you MUST cite them appropriately. Submitted homeworks violating these guidelines will be considered in breach of the academic integrity code.

There will be 6-7 homework assigments over the course of the semester. The final homework grade will be the average of all homework scores with the lowest score dropped.

Laptop policy

I ask that students not use laptops or other electronic devices in class. I will make sure to lecture at a pace that allows for hand-written notes.

Tentative schedule

This is a tentative schedule for the class. I will update this as we go along. I will also post all homeworks and due dates here.

DateLecture Topic(s)ReadingHW OutHW DueQuiz
Aug. 27Probability and asymptotics review, principles of modern cryptography, perfect secrecy and the one-time padA.2, 3.1.2, A.3, 1.2, 1.4, 2.1-2.2HW0,HW1Quiz 1
Sep. 3Labor day: no classHW0 due
Sep. 10Proof of security of the one-time pad, computationally-secure encryption, proofs by reduction, pseudorandom generators and security of PRG+OTP encryption2.2, 2.3, 3.2, 3.2.1, 3.3HW2HW1 dueQuiz 2
Sep. 17Review of PRG and computationally-secure encryption, CPA security, pseudorandom functions, construction of CPA-secure encryption3.4, 3.5
Sep. 24CCA-secure encryption, modes of operation, padding oracle attack3.6, 3.7HW2 dueQuiz 3
Oct. 1Message authentication codes definitions and constructions, CBC-MAC, authenticated encryption, hash function definitions and applications4.1-4.5, 5.1, 5.6HW3Quiz 4
Oct. 8Fall break: no class
Oct. 15Hash functions and birthday attack, domain extension for hash functions, MACs from hash functions, review for midterm5.2, 5.3, 5.4.1HW3 due
Oct. 22Exam (in class)
Oct. 29Practical constructions of symmetric-key primitives, DES, 3DES, AES, Feistel networks6.2, 6.3HW4
Nov. 5Number theory, group theory, cryptographic assumptions8.1, 8.2, 8.3.1, 8.3.2, 8.4.2Midterm 1 due
Nov. 12Key exchange, Public-key encryption, Diffie-Hellman, El Gamal10, 11.1, 11.2.1, 11.4.1, 8.3.3HW5HW4 due
Nov. 19El Gamal, RSA, Paillier, CCA security11.4.1, 11.5.1, 11.5.2, 13.2, 11.2.3
Dec. 3Key encapsulation, Digital signatures, Hash-and-sign, Fiat-Shamir transform and Schnorr signatures, DSA
Dec. 10Exam 2HW6 due


  • NEW Exam 2 will be in class on Monday, Dec. 10
  • NEW Homework 6 is posted: Due Dec. 10 (before class)
  • CLASS on Monday, Nov. 26 is CANCELED
  • Homework 5 is posted: Due Nov. 26 (before class)
  • Homework 4 is posted: Due Nov. 12 (before class)
  • Take-home midterm regrade is due Monday, November 5th (in or before class)
  • Homework 3 is posted: Due Oct. 15 (before class)
  • Homework 2 is posted: Due Sep. 24 (before class)
  • Office hours scheduled for Wednesday Sept. 11 are rescheduled for Thursday, Sept. 12 (3-4:40)
  • HW1 is posted: Due Sep. 10 (before class)
  • HW0 is posted: Due Sep. 3