Dennis Dayanikli

PhD researcher in cryptography at the Hasso Plattner Institute

Portrait of Dennis Dayanikli

About

I am currently a PhD researcher in cryptography at the Hasso Plattner Institute (HPI), working under the supervision of Anja Lehmann. Before that, I completed both my Bachelor’s and Master’s degrees in Mathematics at Ulm University.

My research focuses on the provable security of cryptographic protocols, typically involving the development of security models, a formal security analysis, and the design of new constructions. My main focus is on password-based authentication protocols. I submitted my PhD thesis in January, titled Stronger Security for Password-Based Authentication Protocols.

Publications

An up-to-date list of my publications can be found on dblp.

2025
CCS
Updatable aPAKE: Security Against Bulk Precomputation Attacks
Dennis Dayanikli, Anja Lehmann.
2025
AsiaCCS
Virtual End-to-End Encryption: Analysis of the Doctolib Protocol
Dennis Dayanikli, Laura Holz, Anja Lehmann. To appear.
2024
EuroS&P
(Strong) aPAKE Revisited: Capturing Multi-User Security and Salting
Dennis Dayanikli, Anja Lehmann.
2024
CSF
Provable Security Analysis of the Secure Remote Password Protocol
Dennis Dayanikli, Anja Lehmann.
2023
ESORICS
Password-Based Credentials with Security against Server Compromise
Dennis Dayanikli, Anja Lehmann.
2018
Discrete Mathematics
Approximately locating an invisible agent in a graph with relative distance queries
Dennis Dayanikli, Dieter Rautenbach.

Teaching

An overview of teaching-related experience.

2025, 2024, 2023, 2022, 2021, 2020
Hasso Plattner Institute
Lecture (TA): Introduction to Cryptography
2024, 2023, 2022, 2021
Hasso Plattner Institute
Lecture (TA): Advanced Cryptography
2025
Hasso Plattner Institute
Lecture: Quantum-Safe Cryptography
2024
Hasso Plattner Institute
Seminar: Advanced Topics in Cryptography
2024, 2023
Hasso Plattner Institute
Seminar: Cryptographic Protocols
2023
Hasso Plattner Institute
Master project: Security Analysis of Assertion Tokens in Single Sign-On Solutions
2022
Hasso Plattner Institute
Seminar: Current Topics in Group Messaging
2022
Hasso Plattner Institute
Seminar: Password-based Authentication: Attacks & Defenses
2021
Hasso Plattner Institute
Seminar: Identity Management for End Users
2017
University of Ulm
Student Assistant: Höhere Mathematik für Physiker und Ingenieure
2017, 2013
University of Ulm
Student Assistant: Algebra 1
2016, 2014
University of Ulm
Student Assistant: Elemente der Algebra
2015
University of Ulm
Student Assistant: Optimization and OR 1
2014
University of Ulm
Student Assistant: Algebra 2
2013
University of Ulm
Student Assistant: Analysis 2

Supervision

An overview of supervision activities.

2025
Master Thesis
Key Derivation Schemes for Unlinkability in the EU Identity Wallet
Felix Auringer
2024
Master Thesis
Postcompromise Secure Signatures
Johannes Lang
2024
Master Thesis
Towards Privacy-Preserving Digital Identities: A Formal Approach to Selective Disclosure in Verifiable Credentials
Thure Nebendahl
2024
Master Thesis
Password-Based Credentials with Tamper-Resistance
Armin Wells
2023
Master Thesis
An Analysis of Doctolib's Distributed Envelope Encryption Protocol
Laura Holz
2022
Master Thesis
Password Authentication for End-To-End Encrypted Protocols
Moritz Feldmann

Contact

dennis.dayanikli (at) hpi.de