Cryptography (WS 2022/23)

Course Number 705066 and 705067 | Wintersemester 2022/23

Understand the building blocks of modern cryptographic protocols and learn the basics of cryptanalysis


Cryptography is the mathematical backbone of information security.
This lecture covers the most important building blocks modern cryptographic protocols and their security, including:

  • Authenticated Encryption, hashing, and symmetric primitives (AES-GCM, SHA-3, …)
  • Asymmetric encryption and digital signatures (RSA, DH, DSA, ECC, post-quantum crypto, …)
  • Authentication and key-exchange protocols, including an introduction to advanced privacy-preserving protocols

For all these building blocks, we will have a look at the design ideas and goals behind the algorithm, its security properties in practice, and some cryptanalysis techniques such as differential cryptanalysis. We will cover the necessary mathematical and methodical background so that you can try your own hands in the exercises at breaking ciphers to gain a deeper understanding of their design.


Date Who Lecture 15:00–17:00 (HS i1) Practicals 14:00–15:00 (HS i1 or HS i14)
07.10.2022 ME L1 – Introduction
14.10.2022 ME L2 – Symm. Primitives 1 – Block Ciphers & Friends T1
21.10.2022 ME L3 – Symm. Primitives 2 – Lightweight Crypto T2
28.10.2022 ME L4 – Symm. Primitives 3 – Cryptanalysis T3
04.11.2022 ME L5 – Symm. Modes 1 – Authentication T4
11.11.2022 ME L6 – Symm. Modes 2 – Encryption T5
18.11.2022     KU Exam 1
25.11.2022 ME L7 – Asymmetric Primitives 1 – Factoring, RSA T6
02.12.2022 ME L8 – Asymmetric Primitives 2 – Discrete Log, ECC T7
09.12.2022 ME L9 – Asymmetric Primitives 3 – PQC T8
16.12.2022 ME LA – Protocols 1 – Authentication, Key Exchange T9
13.01.2023 FS LB – Protocols 2 – Advanced Protocols, Privacy TA
20.01.2023     KU Exam 2
27.01.2023   VO Exam

We have one guest talk this year by Fabian Schmid (lecture LB).

All lecture videos from WS 2020/2021 are available as a YouTube playlist.

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:

Previous versions of this course: WS 2021/2022, WS 2020/2021 (YouTube playlist), WS 2019/2020

Administrative Information

Our main communication channel for questions is Discord.

Lecture Exams (VO)

The VO exam is a written exam (for the main exam dates; alternatively, you can contact us for an oral exam any time).
We will ask 4 questions on different topics; you can find lists of example questions to test yourself on the last slide for each lecture.

Please find the exam dates and registration in TUGRAZonline.

Exercise Sheets (KU)

We recommend to visit the KU and VO of Cryptography in the same semester.

In the exercises, you practice the new topics in weekly exercise classes. The tasks are handed out after each week’s lectures, and due for the exercises of the following week, where one student will be selected to present the solution for each of the tasks. Thus, presence is mandatory if you tick any tasks.

You need to solve 50% of all examples to complete the KU. Use the TU Graz TeachCenter to tick the tasks you solved before each class. If you solve more than the required 50%, we will reward you with bonus points that are added to your exam results – for details, please check the lecture slides.
Most of the exercises are pen-and-paper thinking exercises, but each sheet includes a bonus challenge that will require some programming.

Generally, if you tick a task, you must attend the corresponding exercise class on-campus (otherwise, attendance is not required). Alternatively, up to 2 times per semester, you may instead hand in your written, well-readable solution (schriftliche Ersatzabgabe) of all tasks you ticked to your tutor in case you cannot attend a class (e.g., due to Corona). In this case, your tutor may decide to request a short 10-minute virtual assignment interview via Discord on one of the tasks you ticked.

Exercise Exams (KU)

The grades for the KU are based on two exams (and the required 50% tick rate), plus bonus tasks. The dates and place are announced on this website. All students that participate at least in the first exam will receive a grade (positive or negative). There is a “second-chance” exam in February where you can re-take a KU exam (e.g., if you missed the main date or it didn’t go so well).

COVID-19 Info

The lecture (VO) is on campus in HS i1 as long as this is practical, subject to the TU Graz hygiene rules. Recordings of all 2020/21 lectures are available for those students who can’t attend in person. In case on-campus teaching becomes impractical, we’ll switch to virtual YouTube streaming.
The written VO exam is on campus. As an alternative, oral (virtual or on-campus) exams are possible at any time for those unable to attend the written dates in person.

For the weekly exercises (KU), the default is on campus in small groups as long as this is practical. If necessary, we switch to virtual classes on Discord. If you believe this on-campus mode is not feasible for you, contact me.
The two written KU exams are on campus, with a backup date in February for those who can’t attend the main dates.