• Jun.-Prof. Dr.

NILS FLEISCHHACKER

  • Theoretische Kryptographie

Ruhr-University Bochum
Faculty of Computer Science
Theoretical Cryptography
Universitätsstr. 150
44801 Bochum

Room:  MC 0.17

Tel:      +49 (0)234 32-23265

E-Mail: nils.fleischhacker@rub.de

Office hours: By Arrangement

Table of Contents

Curriculum Vitae

I am an Assistant Professor for Cryptography at Ruhr University Bochum. Before moving to Bochum I was a postdoctoral fellow at Johns Hopkins University and Carnegie Mellon University working with Abhishek Jain and Vipul Goyal. In February 2017, I received my PhD in Computer Science from Saarland University, where I was advised by Dominique Schröder. During my PhD I was a research intern at Microsoft Research with Chris Brzuska. I was also a research visitor at University of Maryland, College Park with Jonathan Katz and Dana Dachman-Soled.

  • Foundations of Cryptography
  • Black-Box Separations and Lower Bounds

Publications

2023

[1]
E. Hauck, E. Kiltz, und N. Fleischhacker, „Privacy enhancing primitives“, Universitätsbibliothek, Ruhr-Universität Bochum, Bochum, 2023. doi: 10.13154/294-10514.
[2]
D. Hartmann, E. Kiltz, und N. Fleischhacker, „Limits and applications of digital signatures“, Universitätsbibliothek, Ruhr-Universität Bochum, Bochum, 2023. doi: 10.13154/294-10922.
[1]
N. Fleischhacker, M. Simkin, und Z. Zhang, „Squirrel: efficient synchronized multi-signatures from lattices “, in Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications Security, Los Angeles, Nov. 2022, S. 1109–1123. doi: 10.1145/3548606.3560655.
[2]
N. Fleischhacker, K. G. Larsen, und M. Simkin, „Property-preserving hash functions for hamming distance from standard assumptions“, in Advances in cryptology – EUROCRYPT 2022, Trondheim, Mai 2022, Bd. 13276, S. 764–781. doi: 10.1007/978-3-031-07085-3_26.
 
[1]
N. Fleischhacker und M. Simkin, „On publicly-accountable zero-knowledge and small shuffle arguments“, in Public-key cryptography – PKC 2021, Apr. 2021, Bd. 12711, S. 618–648. doi: 10.1007/978-3-030-75248-4_22.
[2]
N. Fleischhacker und M. Simkin, „Robust property-preserving hash functions for hamming distance and more“, in Advances in cryptology – EUROCRYPT 2021, Zagreb, Juni 2021, Bd. 12696–12698, S. 311–337. doi: 10.1007/978-3-030-77883-5_11.
[1]
N. Fleischhacker, „Interactive non-malleable codes“, Dez. 2019. [Online]. Verfügbar unter: https://nilsfleischhacker.de/publication/interactive-nonmalleable-codes/
[2]
N. Fleischhacker, V. Goyal, A. Jain, A. Paskin-Cherniavsky, und S. Radune, „Interactive non-malleable codes“, in Theory of cryptography, Nürnberg, Nov. 2019, Bd. 11891–11892, S. 233–263. doi: 10.1007/978-3-030-36033-7_9.
[3]
F. Giacon, E. Kiltz, und N. Fleischhacker, „Strengthening public-key cryptography: robust constructions and multi-user security“, Universitätsbibliothek, Ruhr-Universität Bochum, Bochum, 2019. doi: 10.13154/294-6567.
[4]
N. Fleischhacker, T. Jager, und D. Schröder, „On tight security proofs for Schnorr signatures“, Journal of cryptology, Bd. 32, Nr. 2, S. 566–599, 2019, doi: 10.1007/s00145-019-09311-5.
 
[1]
N. Fleischhacker, F. Günther, F. Kiefer, M. Manulis, und B. Poettering, „Pseudorandom signatures“, in ASIA CCS ’2013, 2013, S. 107–118. doi: 10.1145/2484313.2484325.
[1]
M. Manulis, N. Fleischhacker, F. Günther, F. Kiefer, und B. Poettering, „Group signatures: authentication with privacy“, 2012. [Online]. Verfügbar unter: https://www.bsi.bund.de/SharedDocs/Downloads/EN/BSI/Publications/Studies/GruPA/GruPA.pdf?__blob=publicationFile
[1]
N. Fleischhacker, F. Günther, F. Kiefer, M. Manulis, und B. Poettering, „Pseudorandom signatures“, 2011. https://eprint.iacr.org/2011/673

Publications

26 Einträge « ‹ 1 von 3 › »

Alexander Karenin and Elena Kirshanova and Julian Nowakowski, Alexander May

Fast Slicer for Batch-CVP: Making Lattice Hybrid Attacks Practical Proceedings Article

In: Advances in Cryptology (ASIACRYPT 25), 2025.

Links | Schlagwörter: Crypto Flagship, Rank A*/A

Simon Damm, Asja Fischer, Alexander May, Soundes Marzougui, Leander Schwarz, Henning Seidler, Jean-Pierre Seifert, Jonas Thietke, Vincent Quentin Ulitzsch

Solving Concealed ILWE and its Application for Breaking Masked Dilithium Proceedings Article

In: Advances in Cryptology (ASIACRYPT 25), 2025.

Links | Schlagwörter: Crypto Flagship, Rank A*/A

Alexander May, Massimo Ostuzzi, Henrik Ressler

Just Guess: Improved (Quantum) Algorithm for the Underdetermined MQ Problem Artikel Geplante Veröffentlichung

In: Geplante Veröffentlichung.

Links | Schlagwörter: Quantum

Timo Glaser, Alexander May, Julian Nowakowski

Super-Quadratic Quantum Speed-Ups and Guessing Many Likely Keys Artikel Geplante Veröffentlichung

In: Preprint, Geplante Veröffentlichung.

Links | Schlagwörter: Quantum

Alexander May, Massimo Ostuzzi

Multiple Group Action Dlogs with(out) Precomputation Proceedings Article

In: Public Key Cryptography (PKC '25), 2025.

Links | Schlagwörter: Crypto Area

Simon Damm, Nicolai Kraus, Alexander May, Julian Nowakowski, Jonas Thietke

One Bit to Rule Them All - Imperfect Randomness Harms Lattice Signatures Proceedings Article

In: Public Key Cryptography (PKC '25), 2025.

Links | Schlagwörter: Crypto Area

Marcus Brinkmann, Chitchanok Chuengsatiansup, Alexander May, Julian Nowakowski, Yuval Yarom

Leaky McEliece: Secret Key Recovery From Highly Erroneous Side-Channel Information Artikel

In: Transactions on Cryptographic Hardware and Embedded Systems (TCHES), 2025.

Links | Schlagwörter: Crypto Area, Rank A*/A

Sebastian Bitzer, Jeroen Delvaux, Elena Kirshanova, Sebastian Maaßen, Alexander May, Antonia Wachter-Zeh

How to Lose Some Weight - A Practical Template Syndrome Decoding Attack Proceedings Article

In: Coding and Cryptography (WCC 24) and Design, Codes and Cryptography (2025), 2024.

Links | Schlagwörter: Crypto Others

Alexander May, Julian Nowakowski

Too Many Hints - When LLL Breaks LWE Proceedings Article

In: Advances in Cryptology (ASIACRYPT 23), 2023.

Links | Schlagwörter: Crypto Flagship, Rank A*/A

Timo Glaser, Alexander May

How to Enumerate LWE Keys as Narrow as in Kyber/Dilithium Proceedings Article

In: Cryptology and Network Security (CANS 23), S. 75–100, Springer, 2023.

Links | Schlagwörter: Crypto Others

26 Einträge « ‹ 1 von 3 › »

Memberships

  • BITSI – Bochumer Verein zur Förderung der IT-Sicherheit und Informatik
  • CASA – DFG Excellence Cluster
  • QSI – EU Marie Curie Network
  • HGI – Horst Görtz Institute
  • IACR – Cryptology Research

Lectures (Moodle/Notes)

Crypto Challenges

Former PhDs

  1. Önder Askin, 2024
  2. Floyd Zweydinger, 2023
  3. Lars Schlieper, 2022
  4. Alexander Helm, 2020
  5. Andre Esser, 2020
  6. Matthias Minihold, 2019 
  7. Leif Both, 2018
  8. Robert Kübler, 2018
  9. Elena Kirshanova, 2016
  10. Ilya Ozerov, 2016
  11. Gottfried Herold, 2014
  12. Alexander Meurer, 2014
  13. Mathias Herrmann, 2011
  14. Maike Ritzenhofen, 2010

Calvin & Hobbes

Prof. Dr. Nils Fleischhacker

Theoretical Cryptography

Professor / Head of Chair

Address:
Ruhr-University Bochum
Faculty of Computer Science
Theoretical Cryptography
Universitätsstr. 150
--D-44801 Bochum

Room: MC 1/17

Telephone: +49 (0)234 32-23265

Office Hours: By arrangement

E-Mail: nils.fleischhacker@rub.de

Courses



Research

- Foundations of Cryptography
- Black-Box Separations and Lower Bounds


Publications

I am an Assistant Professor for Cryptography at Ruhr University Bochum. Before moving to Bochum I was a postdoctoral fellow at Johns Hopkins University and Carnegie Mellon University working with Abhishek Jain and Vipul Goyal. In February 2017, I received my PhD in Computer Science from Saarland University, where I was advised by Dominique Schröder. During my PhD I was a research intern at Microsoft Research with Chris Brzuska. I was also a research visitor at University of Maryland, College Park with Jonathan Katz and Dana Dachman-Soled.