Dr. Michael Klooß
- Wissenschaftlicher Mitarbeiter (Akademischer Rat)
- Sprechstunden: Nach Vereinbarung / By appointment
- Raum: 271
CS 50.34 - Tel.: +49 721 608-46297
- michael klooss ∂does-not-exist.kit edu
- Am Fasanengarten 5
76131 Karlsruhe
Forschungsinteressen
My research in cryptography is mostly about providing solid foundations for efficient primitives and protocols. A key goal is to find overarching structure, understand and abstract similarities and – in the best case – connect techniques from different areas, ultimately finding natural and (in hindsight) simple solutions to important problems. Consequently, my research includes definitional questions (how to model the security of primitives or protocols), analysis and technical questions (how to prove something secure, and how to construct it), and modularity questions (how to capture techniques under a common intuition or framework).
My current focus is lattice-based cryptography in terms of assumptions, proof systems in terms of constructions, and privacy-preserving signatures in terms of motivation.
Publikationen
Scalable Registration-Based Encryption from Lattices
Klooß, M.; Lai, R. W. F.; Siemer, J. N.; Swarnakar, M.
2026. 2026 IEEE Symposium on Security and Privacy (SP), 2520–2538, Institute of Electrical and Electronics Engineers (IEEE). doi:10.1109/SP63933.2026.00199
Klooß, M.; Lai, R. W. F.; Siemer, J. N.; Swarnakar, M.
2026. 2026 IEEE Symposium on Security and Privacy (SP), 2520–2538, Institute of Electrical and Electronics Engineers (IEEE). doi:10.1109/SP63933.2026.00199
The Fiat—Shamir Transformation of
Attema, T.; Fehr, S.; Klooß, M.; Resch, N.
2026. Journal of Cryptology, 39 (2), 19. doi:10.1007/s00145-025-09569-y
Attema, T.; Fehr, S.; Klooß, M.; Resch, N.
2026. Journal of Cryptology, 39 (2), 19. doi:10.1007/s00145-025-09569-y
Tightly-Secure Blind Signatures in Pairing-Free Groups
Brandt, N.; Hofheinz, D.; Klooß, M.; Reichle, M.
2026. Advances in Cryptology – ASIACRYPT 2025 : 31st International Conference on the Theory and Application of Cryptology and Information Security, Melbourne, VIC, Australia, December 8–12, 2025, Proceedings, Part VI. Ed.: G. Hanaoka, 337–369, Springer Nature Singapore. doi:10.1007/978-981-95-5119-4_11
Brandt, N.; Hofheinz, D.; Klooß, M.; Reichle, M.
2026. Advances in Cryptology – ASIACRYPT 2025 : 31st International Conference on the Theory and Application of Cryptology and Information Security, Melbourne, VIC, Australia, December 8–12, 2025, Proceedings, Part VI. Ed.: G. Hanaoka, 337–369, Springer Nature Singapore. doi:10.1007/978-981-95-5119-4_11
Lattice-Based Proof-Friendly Signatures from Vanishing Short Integer Solutions
Dubois, A.; Klooß, M.; Lai, R. W. F.; Woo, I. K. Y.
2025. Public-Key Cryptography – PKC 2025 – 28th IACR International Conference on Practice and Theory of Public-Key Cryptography, Røros, Norway, May 12–15, 2025, Proceedings, Part I. Ed.: T. Jager, 452 – 486, Springer Nature Switzerland. doi:10.1007/978-3-031-91820-9_15
Dubois, A.; Klooß, M.; Lai, R. W. F.; Woo, I. K. Y.
2025. Public-Key Cryptography – PKC 2025 – 28th IACR International Conference on Practice and Theory of Public-Key Cryptography, Røros, Norway, May 12–15, 2025, Proceedings, Part I. Ed.: T. Jager, 452 – 486, Springer Nature Switzerland. doi:10.1007/978-3-031-91820-9_15
Publicly Verifiable Zero-Knowledge and Post-Quantum Signatures from VOLE-in-the-Head
Baum, C.; Braun, L.; Saint Guilhem, C. D. De; Klooß, M.; Orsini, E.; Roy, L.; Scholl, P.
2023. Advances in Cryptology – CRYPTO 2023 – 43rd Annual International Cryptology Conference, CRYPTO 2023, Santa Barbara, CA, USA, August 20–24, 2023, Proceedings, Part V. Ed.: H. Handschuh, 581–615, Springer Nature Switzerland. doi:10.1007/978-3-031-38554-4_19
Baum, C.; Braun, L.; Saint Guilhem, C. D. De; Klooß, M.; Orsini, E.; Roy, L.; Scholl, P.
2023. Advances in Cryptology – CRYPTO 2023 – 43rd Annual International Cryptology Conference, CRYPTO 2023, Santa Barbara, CA, USA, August 20–24, 2023, Proceedings, Part V. Ed.: H. Handschuh, 581–615, Springer Nature Switzerland. doi:10.1007/978-3-031-38554-4_19
Composable Long-Term Security with Rewinding
Berger, R.; Broadnax, B.; Klooß, M.; Mechler, J.; Müller-Quade, J.; Ottenhues, A.; Raiber, M.
2023. Theory of Cryptography – 21st International Conference, TCC 2023, Taipei, Taiwan, November 29–December 2, 2023, Proceedings, Part IV. Ed.: G. Rothblum, 510 – 541, Springer Nature Switzerland. doi:10.1007/978-3-031-48624-1_19
Berger, R.; Broadnax, B.; Klooß, M.; Mechler, J.; Müller-Quade, J.; Ottenhues, A.; Raiber, M.
2023. Theory of Cryptography – 21st International Conference, TCC 2023, Taipei, Taiwan, November 29–December 2, 2023, Proceedings, Part IV. Ed.: G. Rothblum, 510 – 541, Springer Nature Switzerland. doi:10.1007/978-3-031-48624-1_19
Universally Composable Auditable Surveillance
Fetzer, V.; Klooß, M.; Müller-Quade, J.; Raiber, M.; Rupp, A.
2023. Advances in Cryptology – ASIACRYPT 2023 – 29th International Conference on the Theory and Application of Cryptology and Information Security, Guangzhou, China, December 4–8, 2023, Proceedings, Part II. Ed.: J. Guo, 453 – 487, Springer Nature Singapore. doi:10.1007/978-981-99-8724-5_14
Fetzer, V.; Klooß, M.; Müller-Quade, J.; Raiber, M.; Rupp, A.
2023. Advances in Cryptology – ASIACRYPT 2023 – 29th International Conference on the Theory and Application of Cryptology and Information Security, Guangzhou, China, December 4–8, 2023, Proceedings, Part II. Ed.: J. Guo, 453 – 487, Springer Nature Singapore. doi:10.1007/978-981-99-8724-5_14
Fiat–Shamir Transformation of Multi-Round Interactive Proofs (Extended Version)
Attema, T.; Fehr, S.; Klooß, M.
2023. Journal of Cryptology, 36 (4), Art.-Nr.: 36. doi:10.1007/s00145-023-09478-y
Attema, T.; Fehr, S.; Klooß, M.
2023. Journal of Cryptology, 36 (4), Art.-Nr.: 36. doi:10.1007/s00145-023-09478-y
On Efficient Zero-Knowledge Arguments. Dissertation
Klooß, M.
2023, Februar 20. Karlsruher Institut für Technologie (KIT). doi:10.5445/IR/1000156118
Klooß, M.
2023, Februar 20. Karlsruher Institut für Technologie (KIT). doi:10.5445/IR/1000156118
Fiat-Shamir Transformation of Multi-round Interactive Proofs
Attema, T.; Fehr, S.; Klooß, M.
2022. Theory of Cryptography – 20th International Conference, TCC 2022, Chicago, IL, USA, November 7–10, 2022, Proceedings, Part I. Ed.: E. Kiltz, 113–142, Springer Nature Switzerland. doi:10.1007/978-3-031-22318-1_5
Attema, T.; Fehr, S.; Klooß, M.
2022. Theory of Cryptography – 20th International Conference, TCC 2022, Chicago, IL, USA, November 7–10, 2022, Proceedings, Part I. Ed.: E. Kiltz, 113–142, Springer Nature Switzerland. doi:10.1007/978-3-031-22318-1_5
Sharp: Short Relaxed Range Proofs
Couteau, G.; Goudarzi, D.; Klooß, M.; Reichle, M.
2022. CCS ’22: Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications Security. Ed.: H. Yin Conference: CCS ’22: 2022 ACM SIGSAC Conference on Computer and Communications Security Los Angeles CA USA November 7 - 11, 2022, 609–622, Association for Computing Machinery (ACM). doi:10.1145/3548606.3560628
Couteau, G.; Goudarzi, D.; Klooß, M.; Reichle, M.
2022. CCS ’22: Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications Security. Ed.: H. Yin Conference: CCS ’22: 2022 ACM SIGSAC Conference on Computer and Communications Security Los Angeles CA USA November 7 - 11, 2022, 609–622, Association for Computing Machinery (ACM). doi:10.1145/3548606.3560628
Black-Box Accumulation Based on Lattices
Faller, S. H.; Baumer, P.; Klooß, M.; Koch, A.; Ottenhues, A.; Raiber, M.
2021. Cryptography and Coding : 18th IMA International Conference, IMACC 2021, Virtual Event, December 14–15, 2021, Proceedings. Ed.: M. B. Paterson, 220–246, Springer. doi:10.1007/978-3-030-92641-0_11
Faller, S. H.; Baumer, P.; Klooß, M.; Koch, A.; Ottenhues, A.; Raiber, M.
2021. Cryptography and Coding : 18th IMA International Conference, IMACC 2021, Virtual Event, December 14–15, 2021, Proceedings. Ed.: M. B. Paterson, 220–246, Springer. doi:10.1007/978-3-030-92641-0_11
On Expected Polynomial Runtime in Cryptography
Klooß, M.
2021. Theory of Cryptography : 19th International Conference, TCC 2021, Raleigh, NC, USA, November 8–11, 2021, Proceedings, Part I. Ed.: K. Nissim, 558–590, Springer International Publishing. doi:10.1007/978-3-030-90459-3_19
Klooß, M.
2021. Theory of Cryptography : 19th International Conference, TCC 2021, Raleigh, NC, USA, November 8–11, 2021, Proceedings, Part I. Ed.: K. Nissim, 558–590, Springer International Publishing. doi:10.1007/978-3-030-90459-3_19
Efficient Range Proofs with Transparent Setup from Bounded Integer Commitments
Couteau, G.; Klooß, M.; Lin, H.; Reichle, M.
2021. Advances in Cryptology – EUROCRYPT 2021. Ed.: A. Canteaut, 247–277, Springer International Publishing. doi:10.1007/978-3-030-77883-5_9
Couteau, G.; Klooß, M.; Lin, H.; Reichle, M.
2021. Advances in Cryptology – EUROCRYPT 2021. Ed.: A. Canteaut, 247–277, Springer International Publishing. doi:10.1007/978-3-030-77883-5_9
Black-Box Wallets: Fast Anonymous Two-Way Payments for Constrained Devices
Hoffmann, M.; Klooß, M.; Raiber, M.; Rupp, A.
2020. Proceedings on privacy enhancing technologies, 2020 (1), 165–194. doi:10.2478/popets-2020-0010
Hoffmann, M.; Klooß, M.; Raiber, M.; Rupp, A.
2020. Proceedings on privacy enhancing technologies, 2020 (1), 165–194. doi:10.2478/popets-2020-0010
Efficient Zero-Knowledge Arguments in the Discrete Log Setting, Revisited
Hoffmann, M.; Klooß, M.; Rupp, A.
2019. Proceedings of the 2019 ACM SIGSAC Conference on Computer and Communications Security, 2093–2110, Association for Computing Machinery (ACM). doi:10.1145/3319535.3354251
Hoffmann, M.; Klooß, M.; Rupp, A.
2019. Proceedings of the 2019 ACM SIGSAC Conference on Computer and Communications Security, 2093–2110, Association for Computing Machinery (ACM). doi:10.1145/3319535.3354251
(R)CCA Secure Updatable Encryption with Integrity Protection
Klooß, M.; Lehmann, A.; Rupp, A.
2019. Advances in Cryptology – EUROCRYPT 2019 – 38th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Darmstadt, Germany, May 19–23, 2019, Proceedings, Part I. Ed.: Y. Ishai, 68–99, Springer International Publishing. doi:10.1007/978-3-030-17653-2_3
Klooß, M.; Lehmann, A.; Rupp, A.
2019. Advances in Cryptology – EUROCRYPT 2019 – 38th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Darmstadt, Germany, May 19–23, 2019, Proceedings, Part I. Ed.: Y. Ishai, 68–99, Springer International Publishing. doi:10.1007/978-3-030-17653-2_3
New Techniques for Structural Batch Verification in Bilinear Groups with Applications to Groth-Sahai Proofs
Herold, G.; Hoffmann, M.; Klooß, M.; Ràfols, C.; Rupp, A.
2017. 24th ACM Conference on Computer and Communications Security (ACM CCS 2017), Dallas, TX, October 30 - November 3, 2017, 1547–1564, Association for Computing Machinery (ACM). doi:10.1145/3133956.3134068
Herold, G.; Hoffmann, M.; Klooß, M.; Ràfols, C.; Rupp, A.
2017. 24th ACM Conference on Computer and Communications Security (ACM CCS 2017), Dallas, TX, October 30 - November 3, 2017, 1547–1564, Association for Computing Machinery (ACM). doi:10.1145/3133956.3134068
| Titel | Typ | Semester | Dozent |
|---|---|---|---|
| Post-quantum Cryptography from Lattices | Vorlesung (V) | SS 2026 | Alexander Kühn Robert Brede Dr. Michael Klooß |
| Theoretische Grundlagen der Kryptographie | Vorlesung (V) | WS 25/26 | Prof. Dr. Jörn Müller-Quade Robin Marius Berger Dr. Michael Klooß |
| Theoretische Grundlagen der Kryptographie | Vorlesung (V) | WS 26/27 | Prof. Dr. Jörn Müller-Quade Robin Marius Berger Dr. Michael Klooß |
| Post-Quantum Cryptography | Seminar (S) | SS 2025 | Astrid Ottenhues Dr. Kevin Marcel Tiepelt Prof. Dr. Jörn Müller-Quade Clemens Friedrich Fruböse Roland Gröll Wasilij Beskorovajnov Laurin Benz Dr. Michael Klooß |
| Seminar Advanced Lattice-based Cryptography | Seminar (S) | WS 26/27 | Prof. Dr. Jörn Müller-Quade Alexander Kühn Dr. Johannes Ottenhues Dr. Michael Klooß |
| Titel | Typ | Semester | Dozent |
|---|---|---|---|
| Theoretische Grundlagen der Kryptographie | Vorlesung (V) | WS 22/23 | Prof. Dr. Jörn Müller-Quade |
| Theoretische Grundlagen der Kryptographie | Vorlesung (V) | WS 21/22 | Prof. Dr. Jörn Müller-Quade |
| Seminar Post-Quantum Cryptography | Seminar (S) | WS 21/22 | Marcel Tiepelt |
| Seminar Quantum Information Theory | Seminar | SS 2021 | Prof. Dr. Thorsten Strufe |
| Theoretischen Grundlagen der Kryptographie | Vorlesung (V) | WS 20/21 | |
| Seminar Quantum Information Theory | Seminar (S) | SS 2020 | Prof. Dr. Jörn Müller-Quade |
| Obfustopia | Seminar (S) | WS 19/20 | Julia Kastner |
| Ausgewählte Kapitel der Kryptographie | Vorlesung (V) | SS 2019 | Prof. Dr. Jörn Müller-Quade Michael Klooß Jeremias Mechler |
| Advanced Topics in Lattice-based Cryptography | Seminar (S) | SS 2019 | Prof. Dr. Dennis Hofheinz Akin Ünal Michael Klooß Bogdan Ursu Geoffroy Couteau Lisa Maria Kohl |
| Foundations of Lattice-based Cryptography | Seminar (S) | SS 2019 | Prof. Dr. Dennis Hofheinz Prof. Dr. Jörn Müller-Quade Akin Ünal Michael Klooß Bogdan Ursu Geoffroy Couteau Lisa Maria Kohl |
| Quantum Cryptography | Seminar (S) | WS 18/19 | Prof. Dr. Dennis Hofheinz Prof. Dr. Jörn Müller-Quade Bogdan Ursu Sven Maier Jeremias Mechler Dr. Alexander Koch |
| Quantum Complexity Theory | Seminar (S) | WS 18/19 | Prof. Dr. Dennis Hofheinz Dr. Jessica Koch Akin Ünal Michael Klooß Bogdan Ursu Sven Maier Dr. Alexander Koch |
| Public-Coin Zero-Knowledge Proof Systems | Seminar (S) | WS 18/19 | Prof. Dr. Dennis Hofheinz Prof. Dr. Jörn Müller-Quade Valerie Fetzer Dr.-Ing. Andy Rupp Geoffroy Couteau |
| Non-Interactive Zero-Knowledge Proof Systems | Seminar (S) | WS 18/19 | Prof. Dr. Dennis Hofheinz Prof. Dr. Jörn Müller-Quade Michael Klooß Thomas Agrikola Bogdan Ursu |
| Public-Key Cryptography with Tight Security | Seminar (S) | SS 2018 | Prof. Dr. Dennis Hofheinz Michael Klooß Dr. Jiaxin Pan Bogdan Ursu Dr. Alexander Koch |
| Payment Sytems and Cryptocurrencies | Seminar (S) | SS 2018 | Prof. Dr. Dennis Hofheinz Valerie Fetzer Michael Klooß Dr.-Ing. Andy Rupp Thomas Agrikola |
| Crypto for Real-World Applications | Seminar (S) | WS 17/18 | Prof. Dr. Jörn Müller-Quade Valerie Fetzer Stefanie Fuchs Carmen Manietta Dr.-Ing. Andy Rupp Thomas Agrikola Jeremias Mechler |
| Functional Encryption | Seminar (S) | WS 17/18 | Prof. Dr. Dennis Hofheinz Michael Klooß Dr. Jiaxin Pan Lisa Maria Kohl |