# TU Wien:Advanced Cryptography VU (Fuchsbauer)

## Daten[edit | edit source]

Lecturers | Georg Fuchsbauer |
---|---|

ECTS | 6 |

Alias | Advanced Cryptography (en) |

Department | Logic and Computation |

When | summer semester |

Last iteration | 2021SS |

Language | English |

Links | tiss:192115 |

## Inhalt[edit | edit source]

Points copied from TISS as they turned out to be a perfectly accurate description of the topics that we covered:

- Provable security, the random-oracle model
- Pairing-based cryptography, identity-based encryption
- Zero-knowledge and succinct proof systems
- Lattice-based cryptography (quantum-secure public-key schemes)
- Secure multi-party computation

## Ablauf[edit | edit source]

**2021SS:** Every week on Thursday, there was a live Zoom lecture (with recording, 12 lectures in total). We would get the recording and the slides via student email, usually a day later.

Just the same, there would be an exercise sheet every week about the presented topic which had to be handed in in TUWEL the following week Friday.

At the end, there was a final exam - we were asked if we wanted an oral or written exam, since we were only around 20 people. We then settled for an oral exam for which you had to register for a slot in TISS.

The grading was 50/50 (50% exercises, 50% exam result).

## Benötigte/Empfehlenswerte Vorkenntnisse[edit | edit source]

You must have a solid foundation in Cryptography as presented in courses like Introduction to Modern Cryptography VU (Fuchsbauer), held by the same people as this course. There is a short recap at the beginning, but you are expected to be familiar with basic concepts of cryptography like negligibility and common proof schemes. It also helps to have heard of the "basic" cryptography schemes like RSA, as some of the presented concepts build upon these basic blocks.

Obviously, you also need strong algebraic foundations, just like for the introductory course.

## Vortrag[edit | edit source]

One live online lecture every week (with recording). Depending on the topic, it would be either the lecturer himself or the assistant holding the lecture. You were always allowed to interrupt the talk with questions or discussion points, and both of the presenters were always very eager and happy to discuss any questions together with the participants.

## Übungen[edit | edit source]

You would receive an exercise sheet every week via TUWEL (there were 8 exercise sheets in total). The solved exercises had to be ticked - usually, there were 3 exercises and there were 6 checkboxes (2 per exercise). The idea was that if you solve an exercise only halfway (or are relatively sure that your solution is mostly wrong) then you only check one of the two checkboxes and still get half of the points for that exercise (4 points per exercise - 2*2 points). Additionally, you had to upload your solutions as a PDF in TUWEL. The deadline for this was Friday 12:00 (with the exercise session starting Friday 14:00, so just 2 hours before the start of the session - huge thanks to the administration for this).

During the exercise session, the assistant would call a person for every exercise to present the solution live. However, it was more like a discussion session where the participants would also discuss about your solution and alternative solution possiblities - it was *not* a scored presentation like you remember them from the first-semester maths lectures. You would not get a scoring on your presentation (no "Tafelleistung"). Thus, the atmosphere in these sessions was usually relaxed. Sometimes, the assistant would read through the submissions beforehand and then pick those people who have an interesting or just slightly wrong solution (in order to trigger a discussion), other times he would just pick people at random.

After the sessions, for each exercise sheet, the assistant would look through a random subset of them (and then also only at one randomly selected exercise) and give deductions for wrong solutions. For the exercises that he didn't verify, you would always get the full amount of points that you selected with your checkmarks.

## Prüfung, Benotung[edit | edit source]

We were asked if we wanted an oral or written exam, since we were only around 20 people. We then settled for an oral exam for which you had to register for a slot in TISS. For the exam itself, we had to join a Zoom meeting on the chosen slot time where both the lecturer and the assistant asked questions about their topics. If you struggled on certain questions, you would always get some helping hints to bring you on the right track and to help you answer the question correctly.

After the exam, the lecturer and assistant would go into a breakout room and discuss the grading - after that, they would tell you your score (out of 100 points), after which they asked us for some short feedback on the lecture and exercises.

### Dauer der Zeugnisausstellung[edit | edit source]

**2021SS:** Exam on 2021-06-25, certificate on 2021-07-07 (2 weeks later - they waited until every person registered for an exam had had their exam)

## Zeitaufwand[edit | edit source]

Depends **a lot** on how good you are at mathematical proofs and logical reasoning. Since it's a weekly session, my colleagues and me usually spent the night before the exercise session solving exercises (so like 6-7 hours per exercise sheet - thanks again to the administration team for setting the deadline just 2 hours before the session, otherwise this wouldn't have been possible) and would usually get around 2 out of 3 exercises done. Other people who were more inclined towards such exercises didn't need that much.

## Unterlagen[edit | edit source]

noch offen

## Tipps[edit | edit source]

- Do not do this course if you don't know the basics of cryptography, or you will have a very hard time following along.
- When you are struggling with an exercise, try to solve it at least halfway, so you can still get half of the points for it.
- Sometimes, you can find helpful solutions to similar problems on the internet, which can help you to get on the right track to solve the given exercise. Make sure to not just copy what you find, but to also understand what you are doing.

## Verbesserungsvorschläge / Kritik[edit | edit source]

There isn't much to say for me here - it was a very pleasant experience. The team (lecturer and assistant) played together very well and you could feel that they have an enthusiasm for the topics. They also gave us plenty of room for discussion and brought the material to us in an encouraging way and in a relaxed atmosphere. The exercises were pretty hard sometimes, but I wouldn't expect any less from an advanced cryptography course ^^ If you're eager to learn about advanced cryptography concepts and know the basics, I can fully recommend this lecture.