Hasso-Plattner-Institut25 Jahre HPI
Hasso-Plattner-Institut25 Jahre HPI

Cryptographic Protocols (Sommersemester 2023)

Dozent: Prof. Dr. Anja Lehmann (Cyber Security - Identity Management) , Tarek Galal Abdelsalam (Cyber Security - Identity Management) , Maximilian Johannes Kroschewski (Cyber Security - Identity Management)

Allgemeine Information

  • Semesterwochenstunden: 4
  • ECTS: 6
  • Benotet: Ja
  • Einschreibefrist: 01.04.2023 - 07.05.2023
  • Prüfungszeitpunkt §9 (4) BAMA-O: 16.05.2023
  • Lehrform: Seminar
  • Belegungsart: Wahlpflichtmodul
  • Lehrsprache: Englisch
  • Maximale Teilnehmerzahl: 20

Studiengänge, Modulgruppen & Module

Cybersecurity MA
  • IDMG: Identity Management
    • HPI-IDMG-K Konzepte und Methoden
  • IDMG: Identity Management
    • HDI-IDMG-T Techniken und Werkzeuge
  • IDMG: Identity Management
    • HPI-IDMG-S Spezialisierung
  • CYAD: Cyber Attack and Defense
    • HPI-CYAD-K Konzepte und Methoden
  • CYAD: Cyber Attack and Defense
    • HPI-CYAD-T Techniken und Werkzeuge
  • CYAD: Cyber Attack and Defense
    • HPI-CYAD-S Spezialisierung
IT-Systems Engineering MA
Digital Health MA
Data Engineering MA
Software Systems Engineering MA


In this seminar, we will examine various real-world cryptographic protocols.

Our focus will be on the core functional and security properties addressed by the protocols, their cryptographic solutions, and potential attacks or limitations. The seminar will start with a lecture period (2-3 weeks) where the required cryptographic building blocks are briefly introduced. Students will work in small groups (2 students per topic) on the presentation of a concrete protocol assigned at the beginning of the seminar.

The task of the presentations is to describe the desired functional and security properties, the construction of the protocols (using the previously introduced generic building blocks for a unified treatment throughout the seminar), and how the security of the building blocks contributes to the security of the protocol, possibly accompanied with discussions of real-world attacks. Alongside their presentations, students will create summaries in the form of a handout, which their peers will review. At the end of the seminar, these summaries will be compiled into a report for the benefit of all participants.

More information and a list of papers/protocols can be found in Moodle: https://moodle.hpi.de/course/view.php?id=421


Previous knowledge of cryptography (e.g., attendance of the Introduction to Cryptography lecture) is helpful but not required, as we start with a lecture period to ensure a shared common understanding of the fundamental cryptographic primitives among all attendees.

The lecture period will recap/introduce the abstract definition of the most basic cryptographic building blocks, such as encryption schemes or hash functions, i.e., explain and capture their generic behavior and security properties. How these building blocks are realized is not part of the introduction but also not necessary for the seminar.


A list of protocols and papers is given in the Moodle. In the first session we will give a brief overview of the protocols. Over the following days, participants will rate their preferences on Moodle, and afterwards, get allocated into groups (of two) and assigned a protocol based on their ratings. Ratings will start right after the first session and until 20.04.2023 18:00. If interested in taking a protocol that is not listed, feel free to bring it forward to us by sending an email or coming to our office before the ratings end.


Attendance is compulsory for all participants. Please get in touch with us if you are unable to attend.

At the start of the seminar, you must choose whether to take the course for 6 ECTS or 3 ECTS. The grading will be adjusted based on your choice:

6 ECTS: Presentation (40%), participation (10%), handout (30%), review (20%)
3 ECTS: Presentation (90%), participation (10%)


The seminar will be held Mondays, 11.00 - 12.30 in G3.E.15/16.

Preliminary structure:

  • Weeks 1-2: Chose protocol, lectures
  • Week 3: No seminar (1.Mai)
  • Weeks 4-6: Initial presentation, lectures
  • Week 7: No seminar (Pfingstmontag)
  • Weeks 8-12: Presentations, submit a handout
  • Weeks 13-15: Write and submit reviews