Welcome
Me

I'm PhD student at the Chair for Net­work and Data Se­cu­ri­ty, Horst Görtz Institute for IT Security, Ruhr University Bochum, Germany supervised by Jörg Schwenk and second supervisor Eike Kiltz. My research topics are cryptography and protocol security. You can find my papers at my Google Scholar profile or below.

Contact/Links

Twitter@roeslpa
GitHub/roeslpa
Mailpaul.roesler [at] rub.de
PGP key

Short CV

01/20Research visit with Yevgeniy Dodis at New York University (NYU)
10/19Research visit with Kenny Paterson at Eidgenössische Technische Hochschule Zürich (ETH Zürich)
11/18Research visit with Serge Vaudenay at École polytechnique fédérale de Lausanne (EPFL)
02/18Research visit with Bertram Poettering at Royal Holloway, University of London (RHUL)
10/16 - nowPhD student supervised by Jörg Schwenk and second supervisor Eike Kiltz at Chair for Net­work and Data Se­cu­ri­ty, HGI, Ruhr University Bochum (RUB)
10/19 - nowB.A. Philosophy, Ruhr University Bochum
10/15 - 12/18M.Sc. IT Security, Ruhr University Bochum
04/15 - 07/15Intern at KPMG Security Consulting
09/14 - 02/15 & 10/15 - 09/16Working student at Qabel
10/12 - 09/15B.Sc. IT Security, Ruhr University Bochum

Publications

Determining the Core Primitive for Optimally Secure Ratcheting
Fatih Balli, Paul Rösler, Serge Vaudenay
Preprint: [PDF]

Combiners for AEAD
Bertram Poettering, Paul Rösler
IACR Conference on Fast Software Encryption, FSE 2020
IACR Transactions on Symmetric Cryptology, ToSC Volume 2020, Issue 1

Flexible Authenticated and Confidential Channel Establishment (fACCE): Analyzing the Noise Protocol Framework
Benjamin Dowling, Paul Rösler, Jörg Schwenk
IACR International Conference on Practice and Theory in Public Key Cryptography, PKC 2020: [PDF full version]

Towards Bidirectional Ratcheted Key Exchange
Bertram Poettering, Paul Rösler
IACR International Cryptology Conference, CRYPTO 2018: [Proceedings]
Extended version: Asynchronous ratcheted key exchange [PDF]
Java implementation by Marco Smeets: [Github Repo]

More is Less: On the End-to-End Security of Group Chats in Signal, WhatsApp, and Threema
Paul Rösler, Christian Mainka, Jörg Schwenk
IEEE European Symposium on Security and Privacy, EuroS&P 2018: [PDF full version], [Blog 1], [Blog 2]

Attacking Deterministic Signature Schemes using Fault Attacks
Damian Poddebniak, Juraj Somorovsky, Sebastian Schinzel, Manfred Lochter, Paul Rösler
IEEE European Symposium on Security and Privacy, EuroS&P 2018: [PDF]

Your cloud in my company: Modern rights management services revisited
Martin Grothe, Paul Rösler, Johanna Jupke, Jan Kaiser, Christian Mainka, Jörg Schwenk
International Conference on Availability, Reliability and Security, ARES 2016: [PDF full version]

How to Break Microsoft Rights Management Services
Martin Grothe, Christian Mainka, Paul Rösler, Jörg Schwenk
USENIX Workshop on Offensive Technologies, WOOT 2016: [PDF]

On the End-to-End Security of Group Chats in Instant Messaging Protocols
Master Thesis 2018: [PDF]

Architektur- und Sicherheitsanalyse von Tresorit und Tresorit DRM
Bachelor Thesis 2015: [PDF]

Blog Posts
Why Receipt Notifications increase Security in Signal (05/19): [Link]
Group Instant Messaging: Why blaming developers is not fair but enhancing the protocols would be appropriate (01/18): [Link]
Insecurities of WhatsApp's, Signal's, and Threema's Group Chats (07/17): [Link]

German Short Stories
2019: [PDF]; 2018: [PDF]; 2017: [PDF]; 2016: [PDF]; 2015: [PDF]

Talks

Taming Complexity of Messaging to understand its Security
ZISC Lunch Seminar, ETH Zürich: [PDF slides]
Definitional Foundations of Ratcheting and their Impact on Practice (invited)
Workshop on Secure Messaging, part of IACR Eurocrypt 2019: [PDF slides]
Towards Bidirectional Ratcheted Key Exchange
IACR International Cryptology Conference, CRYPTO 2018: [PDF slides], [Video]
Generalization and Modularization of the ACCE Model
SKECH Workshop 2018: [PDF slides]
Consequences of Complexity in Group Instant Messaging using the Example of WhatsApp and Signal
RuhrSec 2018: [PDF slides], [Video]
More is Less: On the End-to-End Security of Group Chats in Signal, WhatsApp, and Threema
IEEE European Symposium on Security and Privacy, EuroS&P 2018: [PDF slides]
Complexity of Group Communication in Instant Messaging
CryptoAction Symposium 2018: [PDF slides]
Instant Messaging in Gruppen: Schwachstellen trotz sicherer Verschlüsselung (invited)
Paderborner Tag der IT-Sicherheit 2018: [PDF slides]
On the end-to-end security of group chats
IACR Real World Crypto, RWC 2018: [PDF slides], [Video]
Datenschutz und Sicherheit von Instant-Messaging-Protokollen
a-i3/BSI-Symposium 2017: [PDF slides]

Paul Rösler + 10.02.2020