Applied Cryptography 2
Cryptanalytic attacks and how they guide cryptographic design
Table of Content
Cryptanalytic attacks define the security of cryptographic algorithms, and understanding them is crucial to understand cryptographic design. This lecture aims to give you some in-depth knowledge of several recent state-of-the-art topics in cryptography, with a focus on cryptanalysis. Topics to be covered include:
- Modern algorithms for factoring
- Cryptanalysis of block ciphers
- Cryptanalysis of hash functions
- Algebraic attacks
- Lattices and continued fractions in cryptanalysis
- Multi-party computation
In the exercises, you will implement some of these attacks to solve cryptanalytic challenges.
In the seminar, additional selected topics may be presented by participants — see below for a list of suggested topics.
COVID-19 Exam Rules
To comply with the TU Graz COVID-19 guidance, the exams held during summer term 2020 will follow special rules.
The written exam dates have fewer seats available; we will adjust the number of exam dates according to demand.
If you are reluctant to participate in an on-campus exam (e.g., risk group), contact email@example.com to arrange a virtual oral exam.
The question format and general rules (90 minutes, closed-book, etc.) for the written exams remain unchanged, but please observe the TU Graz hygiene guidelines (see below).
Virtual oral exams are conducted via WebEx and obviously cover the same content, but the question format and duration is adapted for the medium (shorter, more interactive, order of questions set by examiner).
You can find upcoming exam dates in TUGRAZonline. If no upcoming dates are listed, ask us!
|05.03.2020||DK||L1 – Factoring and Continued Fractions|
|12.03.2020||DK||L2 – Secure Multi-Party Computation 1|
|19.03.2020||DK||L3 – Secure Multi-Party Computation 2|
|26.03.2020||ME||L4 – Lattices|
|02.04.2020||ME||L5 – Differential Cryptanalysis|
|23.04.2020||ME||L6 – Linear Cryptanalysis|
|30.04.2020||ME||L7 – Tools for Cryptanalysis|
|07.05.2020||MS||L8 – Algebraic Attacks|
|14.05.2020||CR||L9 – Hash Function Cryptanalysis|
|28.05.2020||MS||L10 – Advanced Differential Attacks|
|04.06.2020||T4||S1 – Password Hashing|
|04.06.2020||T7||S2 – Authenticated Encryption: OCB|
|18.06.2020||T6||S3 – Post-Quantum Crypto|
|18.06.2020||T5||S4 – (Fully) Homomorphic Encryption|
|25.06.2020||T2||S5 – Algebraic Attacks|
|19.03.2020||T1 – Asymmetric Cryptanalysis and MPC (assignment, skeleton)|
|23.04.2020||Q1 – Asymmetric Cryptanalysis and MPC, Question Session (slides)|
|07.05.2020||T2 – Symmetric Cryptanalysis (assignment, slides)|
|04.06.2020||Q2 – Symmetric Cryptanalysis, Question Session (slides, tikz)|
Important dates and deadlines
|01.03.2020||VO/KU registration deadline (TUGRAZonline)|
|19.03.2020||Team registration deadline (STicS)|
|19.03.2020||Assignment 1 release|
|23.04.2020||Assignment 1 question time|
|30.04.2020||Assignment 1 submission (23:59)|
|07.05.2020||Assignment 2 release|
|04.06.2020||Assignment 2 question time|
|12.06.2020||Assignment 2 submission (23:59)|
|02.07.2020||VO written exam|
In the exercises, you implement cryptanalysis techniques from the lecture in teams of 2. To get a grade, you submit your implementations for 2 assignments, which we will discuss with you in a final interview ("Abgabegespräch"). Use the Student Tick System (STicS) to register your team and upload your submissions. We usually won't need the 16:30–17:15 KU timeslots (except for question times and seminar presentations).
Lecture exams and seminar talks (VO)
There are 2 ways to get a grade for the VO:
- Exam mode: Write exam at the end of the term or take an oral exam later
- Seminar mode: Participate actively in KU+VO and give a seminar presentation in one of the last lectures (45 minutes)
You can find the exam dates and registration in TUGRAZonline.
Suggested seminar topics include:
- Discrete Logarithm Problem
- Block Ciphers: MitM Attacks, Biclique, etc.
- Block Ciphers: Lightweight Crypto
- Block Ciphers: Statistical Attacks
- Block Ciphers: Division Property
- Hash Functions: Multi-Collisions
- Hash Functions: Rebound Attack
- Authenticated Encryption: Modes, Robustness, Security notions, etc.
- Authenticated Encryption: Permutation-based Cryptography, Tweakable Block Ciphers, etc.
- Algebraic Attacks: Gröbner Basis, etc.
- Elliptic-Curve Cryptography: Advanced topics
- Lattices: The NTRU cryptosystem
- Lattices: Learning with errors
- Selected Topics: Tools in Symmetric Crypto (MILP, SAT, etc.)
- Selected Topics: Backdoors in Cryptography
- Selected Topics: Password Hashing
- Selected Topics: Secure Multi-Party Computation
- Selected Topics: (Fully) Homomorphic encryption
- Selected Topics: Error correcting codes and cryptography
The lecture slides are reasonably self-contained, but often briefly phrased.
If you prefer full-text resources, you may find some of the following books interesting:
- The Block Cipher Companion, by L.R. Knudsen and M.J.B. Robshaw
- An Introduction to Mathematical Cryptography, by J. Hoffstein, J. Pipher, and J.H. Silverman