Cryptography and
Communications Security



  1. There are 4 quizzes planned, each 20min at the beginning of a class.

  2. Dates are: 10/09, 10/16, 11/09, and 12/04

Download Quiz 1, 10/09

Download Quiz 2, 10/16

Download Quiz 3, 11/09

Download Quiz 4, 12/04


  1. Moreover, there will be “homework” assignments handed out at the end of every 2nd week. They are due until the next cycle, i.e., within 14 days. Details will be written on the assignments. Please send solutions by mail.

Download Assignment 1, 09/18, due until 10/02

Download Assignment 2, 10/02, due until 10/16

Download Assignment 3, 10/16, due until 10/30

Download Assignment 4, 10/30, due until 11/13

Download Assignment 5, 11/13, due until 11/27

Download Assignment 6, 11/27, due until 12/11


  1. The Midterm will take place during class on October 23rd.

  2. Download Midterm


  1. During the last three classes, i.e., Dec. 7th, 11th, and 14th, students will present their own “research projects” in 30min each (25min talk + 5 min questions). For this, each student will work on a specific topic of his/her choice, write a 2 pages report, and finally present during class.

  2. Students should send me suggestions on what topic to work on until the Midterm exam (October 23rd). I will then approve suggestions. Topics can either be something not at all covered in class or something much more deeply investigated than in class. Students are welcome to get some advice from me. Possible topics could be, but are not limited to,

  1. LFSR and Berlekamp-Massey

  2. Rotor machines

  3. Linear Cryptanalysis (applied to FEAL or DES)

  4. Differential Cryptanalysis (applied to FEAL or DES)

  5. MD5 and its analysis

  6. SHA-3

  7. Selecting cryptographic key sizes

  8. Other public-key schemes, e.g., Paillier’s

  9. Advanced topics, e.g., Private Information Retrieval, Oblivious RAM, Fully homomorphic encryption


  1. Midterm: 30%

  2. Projects: 25%

  3. Quizzes: 20%

  4. Homework: 20%

  5. Participation: 5%

The software Cryptool is available for download at:

Room and Time   

  1. 108 West Village H

  2. Tuesdays and Fridays, 9:50am – 11:30am


  1. Erik-Oliver Blass

  2. 208B West Village H

  3. blass AT (add “[CS6750]” to the subject of message)

Office Hours: Wednesdays, 2:00pm - 4:00pm


Here is a (tentative) list of topics that will be covered during classes.

  1. Introduction and Historical Cryptography

  2. Symmetric Cryptography: Randomness, Stream Cipher, Block Cipher

  3. Message Authentication and Hash Functions

  4. Key Management and PKI 

  5. Number Theory, Cryptographic Assumptions

  6. Public Key Cryptography

  7. Signatures 

  8. Zero Knowledge Proofs and Secret Sharing

  9. Selected topics in Cryptography and Security