About me

Name

MSc Nico Kevin Christopher Mexis

Born

1999

Birthplace

Bad Reichenhall, Germany

Domicile

Passau, Germany

Email

info (at) femtopedia (dot) de

Current status

Research assistant/PhD student in the CySeReS-KMU project

Do not send me emails about job opportunities or issues on some of my GitHub projects. For the latter, use the appropriate issue form or discussions!

Online Presence

• Google Scholar
• Web of Science
• ORCID
• ResearchGate
• University of Passau
• LinkedIn
• Dev.to
• GitHub

Awards

• 37th Kryptotag: Best Abstract Award (co-authored paper)
• ICCE 2024: Best Session Presentation Award for Tolga Arul (co-authored paper, Certificate)
• SIGCOMM 2021 Student Research Competition (SRC): Third place winner in the Undergraduate Category (Letter, Medal)

Research and Publications

You can also find all these entries as BibTeX files here

Theses

• N. Mexis. A Comprehensive Comparison of Fuzzy Extractor Schemes Employing Different Error Correction Codes. M.Sc. thesis, University of Passau, Passau, Germany, October 2023. DOI 10.15475/ccfesedecc.2023.
• N. Mexis. Fuzzy Extractors unter Einsatz von Low-Density Parity-Check Codes. B.Sc. thesis, University of Passau, Passau, Germany, July 2021. DOI 10.13140/RG.2.2.30714.26562.

First author

• N. Mexis, N. A. Anagnostopoulos, S. Katzenbeisser, E. B. Kavun, S. Tehranipoor, and T. Arul. Achieving Error-Free Lightweight Authentication with DRAM-Based Physical Unclonable Functions. IEEE Transactions on Circuits and Systems I: Regular Papers, 72(2):637-646, February 2025. ISSN 1558-0806. DOI 10.1109/TCSI.2024.3480852.
• N. Mexis, S. Chen, S. Katzenbeisser, T. Arul, and N. A. Anagnostopoulos. Tailored Raspberry Pi 3B+ Software for the Implementation of Hardware Security Primitives Based on Commercial Off-the-Shelf Devices. In 2024 Zooming Innovation in Consumer Technologies Conference (ZINC), pages 90-95, Novi Sad, Serbia, May 2024. IEEE. DOI 10.1109/ZINC61849.2024.10579292.
• N. Mexis, N. A. Anagnostopoulos, T. Arul, and S. Katzenbeisser. An Analysis of the Effects of Temperature on the Performance of ReRAM-Based TRNGs. crypto day matters 36, March 2024. DOI 10.18420/CDM-2024-36-02.
• N. Mexis, N. A. Anagnostopoulos, S. Katzenbeisser, and T. Arul. An Analysis of the Effects of Temperature on the Performance of ReRAM-Based TRNGs. Workshop on "Nano-Security: From Nano-Electronics to Secure Systems" (co-located with the 27th Design, Automation and Test in Europe Conference & Exhibition (DATE 2024), as Workshop 03), March 2024.
• N. Mexis, T. Arul, N. A. Anagnostopoulos, F. Frank, S. Böttger, M. Hartmann, S. Hermann, E. B. Kavun, and S. Katzenbeisser. Spatial Correlation in Weak Physical Unclonable Functions: A Comprehensive Overview. In 2023 26th Euromicro Conference on Digital System Design (DSD), pages 70-78, Golem, Albania, September 2023. IEEE. DOI 10.1109/DSD60849.2023.00020.
• N. Mexis, N. A. Anagnostopoulos, T. Arul, E. B. Kavun, and S. Katzenbeisser. An Improved Machine-Learning Model for the Identification and Classification of Memory-Based PUF Responses. crypto day matters 35, May 2023. DOI 10.18420/CDM-2023-35-03.
• N. Mexis, N. A. Anagnostopoulos, T. Arul, F. Frank, and S. Katzenbeisser. Fuzzy Extractors using Low-Density Parity-Check Codes. crypto day matters 33, September 2021. DOI 10.18420/CDM-2021-33-41.
• N. Mexis, N. A. Anagnostopoulos, S. Chen, J. Bambach, T. Arul, and S. Katzenbeisser. A Design for a Secure Network of Networks Using a Hardware and Software Co-Engineering Architecture. In Proceedings of the SIGCOMM '21 Poster and Demo Sessions, SIGCOMM '21, pages 65-67, New York, NY, USA, August 2021. Association for Computing Machinery. ISBN 9781450386296. DOI 10.1145/3472716.3472849.
• N. Mexis, N. A. Anagnostopoulos, S. Chen, J. Bambach, T. Arul, and S. Katzenbeisser. A Lightweight Architecture for Hardware-Based Security in the Emerging Era of Systems of Systems. ACM Journal on Emerging Technologies in Computing Systems, 17(3):1-25, June 2021. ISSN 1550-4832. DOI 10.1145/3458824.
• N. Mexis, C. Bognitschar, J. Klinke, N. A. Anagnostopoulos, J. H. Chang, T. Arul, A. E. George, and S. Katzenbeisser. Enhancing Data Security with Chaos-Based Cryptography: A Rössler Circuit Implementation. crypto day matters 37, submitted for publication.
• N. Mexis, B. Lill, Y. Doleh, and S. Katzenbeisser. Exposing the Gaps: The State of Supply Chain Coverage in Current Security Standards. In Information Security Education, Cham, Switzerland, submitted for publication. Springer Nature Switzerland.

Co-author

• B. Lill, C. Sauerwein, A. Zeisler, C. Hochstrasser, and N. Mexis. Assessing Cybersecurity Readiness Among SME. In Proceedings of the 27th International Conference on Enterprise Information Systems - Volume 2: ICEIS, pages 253-263, Porto, Portugal, April 2025. INSTICC, SciTePress - Science and Technology Publications. ISBN 978-989-758-749-8. DOI 10.5220/0013353400003929.
• N. Joshi, N. A. Anagnostopoulos, N. Mexis, S. Neisarian, J. H. Chang, O. Millwood, T. Arul, S. Katzenbeisser, and E. B. Kavun. Error-Resilient PUF-Based Authentication on IoT Edge Devices Using Machine Learning. In 2025 IEEE International Conference on Consumer Electronics (ICCE), pages 1-6, Las Vegas, NV, USA, January 2025. IEEE. DOI 10.1109/ICCE63647.2025.10929847.
• E. M. Bahoum, N. Mexis, S. Katzenbeisser, T. Arul, and N. A. Anagnostopoulos. Testing Temperature-Dependent Resistors as Potential Physical Unclonable Functions. In 2024 IEEE 10th World Forum on Internet of Things (WF-IoT), pages 407-413, Ottawa, ON, Canada, November 2024. IEEE. DOI 10.1109/WF-IoT62078.2024.10811170.
• T. Arul, N. Mexis, A. E. George, F. Frank, N. A. Anagnostopoulos, and S. Katzenbeisser. Investigation Of Commercial Off-The-Shelf ReRAM Modules For Use As Runtime-Accessible TRNG. In 2024 27th Euromicro Conference on Digital System Design (DSD), pages 33-42, Paris, France, August 2024. IEEE. DOI 10.1109/DSD64264.2024.00014.
• N. A. Anagnostopoulos, A. E. George, N. Mexis, T. Arul, S. Katzenbeisser, R. Picos, and S. G. Stavrinides. The Synchronisation is the Message: Real-World Encrypted Communication Based on Synchronised Chaotic Circuits Without Using a Dedicated Synchronisation Line. In 2024 13th International Conference on Modern Circuits and Systems Technologies (MOCAST), pages 1-6, Sofia, Bulgaria, June 2024. IEEE. DOI 10.1109/MOCAST61810.2024.10615650.
• A. E. George, E. Gelóczi, N. Mexis, T. Arul, S. Katzenbeisser, S. G. Stavrinides, R. Picos, and N. A. Anagnostopoulos. Real-World Secure Communication based on Synchronised Lorenz Chaotic Circuits. In 2024 13th International Conference on Modern Circuits and Systems Technologies (MOCAST), pages 1-6, Sofia, Bulgaria, June 2024. IEEE. DOI 10.1109/MOCAST61810.2024.10615733.
• A. Tekles, N. Mexis, and S. Katzenbeisser. Memristors in the Context of Security: A Brief Meta-Review of the State of the Art. Preprints, May 2024. DOI 10.20944/preprints202405.1555.v1.
• J. Abbott and N. Mexis. Cyclotomic Factors and LRS-Degeneracy, March 2024. DOI 10.48550/arXiv.2403.08751.
• N. A. Anagnostopoulos, N. Mexis, S. Katzenbeisser, E. B. Kavun, and T. Arul. Neuromorphic and In-Memory Computing Based on Memristive Circuits for Predictive Maintenance and Supply-Chain Management and Security. Workshop on "Nano-Security: From Nano-Electronics to Secure Systems" (co-located with the 27th Design, Automation and Test in Europe Conference & Exhibition (DATE 2024), as Workshop 03), March 2024.
• A. Tekles, T. Arul, N. Mexis, S. Katzenbeisser, and N. A. Anagnostopoulos. Memristors in the Context of Security and AI. Workshop on "Nano-Security: From Nano-Electronics to Secure Systems" (co-located with the 27th Design, Automation and Test in Europe Conference & Exhibition (DATE 2024), as Workshop 03), March 2024.
• N. A. Anagnostopoulos, N. Mexis, Y. Fan, S. S. Bartsch, T. Schaier, S. Katzenbeisser, and T. Arul. Studying the Effects of Prolonged Thermal Stress Aiming to Induce Artificial Aging on DRAM Retention-Based Physical Unclonable Functions. In 2024 IEEE International Conference on Consumer Electronics (ICCE), pages 1-6, Las Vegas, NV, USA, January 2024. IEEE. DOI 10.1109/ICCE59016.2024.10444494.
• F. Frank, S. Böttger, N. Mexis, N. A. Anagnostopoulos, A. Mohamed, M. Hartmann, H. Kuhn, C. Helke, T. Arul, S. Katzenbeisser, and S. Hermann. CNT-PUFs: Highly Robust and Heat-Tolerant Carbon-Nanotube-Based Physical Unclonable Functions. Nanomaterials, 13(22), November 2023. ISSN 2079-4991. DOI 10.3390/NANO13222930.
• N. A. Anagnostopoulos, N. Mexis, S. Böttger, M. Hartmann, A. Mohamed, S. Hermann, S. Katzenbeisser, S. G. Stavrinides, and T. Arul. A Method to Construct Efficient Carbon-Nanotube-Based Physical Unclonable Functions and True Random Number Generators. In 2023 26th Euromicro Conference on Digital System Design (DSD), pages 61-69, Golem, Albania, September 2023. IEEE. DOI 10.1109/DSD60849.2023.00019.
• N. A. Anagnostopoulos, N. Mexis, E. Gelóczi, E. B. Kavun, S. Katzenbeisser, and T. Arul. An Evaluation of the Security and the Privacy of a Novel Single Sign-On System Based on Physical Unclonable Functions. In 2023 IEEE 13th International Conference on Consumer Electronics - Berlin (ICCE-Berlin), pages 76-81, Berlin, Germany, September 2023. IEEE. DOI 10.1109/ICCE-Berlin58801.2023.10375684.
• N. A. Anagnostopoulos, A. Braml, N. Mexis, F. Frank, S. Böttger, M. Hartmann, S. Hermann, E. B. Kavun, S. Katzenbeisser, and T. Arul. Practical Non-Invasive Probing Attacks Against Novel Carbon-Nanotube-Based Physical Unclonable Functions, July 2023. DOI 10.48550/arXiv.2307.01041.
• N. A. Anagnostopoulos, N. Mexis, E. B. Kavun, S. Katzenbeisser, and T. Arul. Neuromorphic and In-Memory Computing Based on Memristive Circuits for Predictive Maintenance and Supply-Chain Security, July 2023. DOI 10.36227/techrxiv.23721990.
• S. Böttger, F. Frank, N. A. Anagnostopoulos, N. Mexis, A. Mohamed, M. Hartmann, T. Arul, S. Hermann, and S. Katzenbeisser. CNT-PUFs: Highly Robust and Heat-Tolerant Carbon-Nanotube-Based Physical Unclonable Functions for Stable Key Generation, July 2023. DOI 10.36227/techrxiv.23621829.
• E. Nazarenko, N. A. Anagnostopoulos, S. G. Stavrinides, N. Mexis, F. Frank, T. Arul, and S. Katzenbeisser. Real-World Chaos-Based Cryptography Using Synchronised Chua Chaotic Circuits, July 2023. DOI 10.36227/techrxiv.21030466.
• E. Gelóczi, N. A. Anagnostopoulos, N. Mexis, Y. Fan, M. U. Saleem, A. Schaller, F. Klement, F. Frank, T. Arul, and S. Katzenbeisser. Testing the Robustness of Physical Unclonable Functions Implemented on Commercial Off-the-Shelf NAND Flash Memories Using Programming Disturbances to Temperature and Voltage Variations. 11th International Workshop on Cryptography, Robustness, and Provably Secure Schemes for Female Young Researchers (CrossFyre 2022), October 2022. URL https://crossfyre22.github.io/docs/Geloczi.pdf. Presented in the 12th IEEE International Conference on Consumer Electronics - Berlin (ICCE-Berlin 2022).
• N. A. Anagnostopoulos, Y. Fan, M. U. Saleem, N. Mexis, F. Frank, T. Arul, and S. Katzenbeisser. On the Sustainability of Lightweight Cryptography Based on PUFs Implemented on NAND Flash Memories Using Programming Disturbances, September 2022. DOI 10.36227/techrxiv.19529263.
• N. A. Anagnostopoulos, Y. Fan, M. U. Saleem, N. Mexis, E. Gelóczi, F. Klement, F. Frank, A. Schaller, T. Arul, and S. Katzenbeisser. Testing Physical Unclonable Functions Implemented on Commercial Off-the-Shelf NAND Flash Memories Using Programming Disturbances. In 2022 IEEE 12th International Conference on Consumer Electronics (ICCE-Berlin), pages 1-9, Berlin, Germany, September 2022. IEEE. DOI 10.1109/ICCE-Berlin56473.2022.10021310.
• E. Nazarenko, N. A. Anagnostopoulos, S. G. Stavrinides, N. Mexis, F. Frank, T. Arul, and S. Katzenbeisser. Real-World Chaos-Based Cryptography Using Synchronised Chua Chaotic Circuits, August 2022. DOI 10.48550/arXiv.2210.11299.
• E. Gelóczi, N. Mexis, N. A. Anagnostopoulos, F. Frank, T. Arul, S. G. Stavrinides, and S. Katzenbeisser. Secure Communication via Chaotic Cryptography. crypto day matters 34, June 2022. DOI 10.18420/CDM-2022-34-01.
• R. Suragani, E. Nazarenko, N. A. Anagnostopoulos, N. Mexis, and E. B. Kavun. Identification and Classification of Corrupted PUF Responses via Machine Learning. In 2022 IEEE International Symposium on Hardware Oriented Security and Trust (HOST), pages 137-140, McLean, VA, USA, June 2022. IEEE. DOI 10.1109/HOST54066.2022.9839919.
• N. A. Anagnostopoulos, Y. Fan, M. U. Saleem, N. Mexis, F. Frank, and T. Arul. On the Sustainability of Lightweight Cryptography Based on PUFs Implemented on NAND Flash Memories Using Programming Disturbances, April 2022. DOI 10.48550/arXiv.2204.02498.
• N. A. Anagnostopoulos, Y. Fan, M. U. Saleem, N. Mexis, F. Frank, T. Arul, and S. Katzenbeisser. On the Sustainability of Lightweight Cryptography Based on Flash PUFs. Workshop on "Sustainability in Security & Security for Sustainability" (co-located with the 25th Design, Automation and Test in Europe Conference & Exhibition (DATE 2022), as Workshop 09), March 2022.
• J. H. Chang, S. Neisarian, N. Mexis, N. A. Anagnostopoulos, T. Arul, and E. B. Kavun. Ternary PUF-based Secure Mutual Authentication Using RNNs for Sequence Learning in Response Classification. In 2025 21th International Conference on Synthesis, Modeling, Analysis and Simulation Methods and Applications to Circuit Design (SMACD), pages 1-4, Istanbul, Türkiye, submitted for publication. IEEE.
• E. Geloczi, N. Mexis, H. Pöhls, B. Holler, and S. Katzenbeisser. IoTCat: A Multidimensional Approach to Categorize IoT Devices. In Applied Cryptography and Network Security Workshops, Cham, Switzerland, submitted for publication. Springer Nature Switzerland.
• S. Neisarian, E. M. Bahoum, N. Mexis, T. Arul, S. Katzenbeisser, and N. A. Anagnostopoulos. Exploring the Uniqueness of Pt100 and Pt1000 Temperature Sensors for Hardware Security Applications. crypto day matters 37, submitted for publication.

Others

• N. Mexis, B. Lill, Y. Doleh, and S. Katzenbeisser. Supplementary Material for the Work "Exposing the Gaps: The State of Supply Chain Coverage in Current Security Standards". Universität Passau, OPUS Dokumentenserver, March 2025. URN urn:nbn:de:bvb:739-opus4-15633.
• T. Arul, N. Mexis, and N. A. Anagnostopoulos. NIST test results for the paper "Towards a Practical Runtime-Accessible True Random Number Generator Based on Commercial Off-The-Shelf Resistive Random Access Memory Modules", August 2024. DOI 10.21227/ZTAS-P887.
• N. A. Anagnostopoulos, N. Mexis, and T. Arul. Random Number Generation. Encyclopedia, March 2023. URL https://encyclopedia.pub/entry/42356.

OEIS Entries

• A355667: Least number phi(k) such that n * phi(k) < k, where phi is Euler’s totient function

Professional Activities

• Web Chair of the IEEE World Technology Summit 2025 (IEEE WTS 2025)
• Web Chair of the 14th IEEE International Conference on Consumer Electronics (IEEE ICCE Berlin 2025)
• IEEE Germany Section Chapter Vice Chair of Consumer Technology Society Chapter (CT08), 2024-2025

Teaching

Courses

WS 24/45

• 5767UE Hardware-Oriented Security
• 5105UE Technische Informatik
• 5766S Masterseminar Security Engineering

SS 24

• 5766S Masterseminar Security Engineering

WS 23/24

• 5766S Masterseminar Security Engineering

SS 23

• 5204UE Rechnerarchitektur

WS 22/23

• 5000 Mathe Brückenkurs

WS 21/22

• 5000 Mathe Brückenkurs

WS 20/21

• 5000 Mathe Brückenkurs

Supervised Theses

• Abin Babu. Evaluation and Refinement of a Physical Unclonable Function (PUF) Implemented on a Flash Memory Under Nominal Conditions and Aging Stress. M.Sc. Thesis, University of Passau, Passau, Germany, April 2025.
• Zhidan Guan. Degradation of NAND Flash PUFs After Aging: An Investigation Into the Impact of Temperature. M.Sc. Thesis, University of Passau, Passau, Germany, January 2025.
• Joseph He Chang. Ternary PUF-based Secure Mutual Authentication Using Recurrent Neural Networks for Sequence Learning in Response Classification. M.Sc. Thesis, University of Passau, Passau, Germany, December 2024.
• Emine Gün. Utilizing Asymmetric Cryptography for PUF-Based Security Applications Without the Need for an Enrollment Phase in a Secure Environment. M.Sc. Thesis, University of Passau, Passau, Germany, November 2024.
• Salah-Eddine Laayoun. Analyzing the Effectiveness of Secure Communication Protocols in Converged IT/OT Environments: A Comprehensive Review. M.Sc. Thesis, University of Passau, Passau, Germany, August 2024.
• Panagiotis Kessanidis. Comparison of Two Different Resistive Random-Access Memories Acting as True Random Number Generators Under Varying Temperatures. B.Sc. Thesis, University of Passau, Passau, Germany, June 2024.
• Mariam Elsharif. Authentication of DRAM PUFs Using Random Forest Machine Learning. M.Sc. Thesis, University of Passau, Passau, Germany, May 2024.
• Yousef Ghassan Yousef Doleh. A Comparative Analysis of Mappings Between Information Security Standards. M.Sc. Thesis, University of Passau, Passau, Germany, March 2024.
• Johannes Hölzlwimmer. Wenn die Temperatur den Zufall beeinflusst: Eine Untersuchung von Resistive Random-Access Memory-basierten Zufallszahlengeneratoren. B.Sc. Thesis, University of Passau, Passau, Germany, December 2023.

Projects for Procrastination

• CoCoA 5:
  Status: In progress
  Code contributor and bug reporter.
• Forked dex2jar:
  Status: In progress
  Fork of dex2jar providing many new possibilities and bug fixes.
• MC Mod Archive:
  Status: In progress
  A huge Minecraft Mod Archive.
• FakeTraveler:
  Status: In progress
  Current maintainer of the famous location mocking app for Android.
• ECC:
  Working Time: ~80 hours (incl. Research)
  Status: Done since 2023
  C++ Library for my Master Thesis. Provides a library for handling some ECCs in C++ using CoCoALib.
• LDPC:
  Working Time: ~50 hours (incl. Research)
  Status: Done since 2021
  Java Library for my Bachelor Thesis. Provides a library for handling binary LDPC Codes in Java.
• Fuzzy Extractors:
  Working Time: ~20 hours (incl. Research)
  Status: Done since 2021
  Java Library for my Bachelor Thesis. Provides a library for Fuzzy Extractors in Java.
• StudiPassau:
  Status: In progress
  Flutter app providing easy and fast access to the schedule, mensa plan etc. of the University of Passau.
• Catcher 2:
  Status: In progress
  Flutter package providing easy error handling - direct integration of Sentry and Emails included!
• Flutter Web Auth 2:
  Status: In progress
  Flutter/Dart package providing easy access to authentication using custom tabs.
• oauth2_client:
  Status: In progress
  Flutter/Dart package providing easy access to OAuth2 functionality.
• Balkon’s WeaponMod: Legacy (Download):
  Working Time: too much
  Status: In progress
  A direct port of the original Balkon’s WeaponMod Minecraft mod for modern versions of the game.
• Bytecode Viewer:
  Working Time: ~30 hours
  Status: In progress
  Moderator and regular contributor in the popular reverese engineering suite
• YAMBZ (Yet another Mandelbrot Zoom):
  Working Time: ~25 hours
  Computing Time: ~10 hours
  Status: Done since January 2020
  The original image’s file size is around 797MB in PNG-format.
• Some Nebulabrot attempts II (Source Code):
  Working Time: ~2 hours
  Computing Time: ~1 hour
  Status: Done since July 2021
  
• Some Nebulabrot attempts:
  Working Time: ~3 hours
  Computing Time: ~10 minutes
  Status: Done since February 2020
  
• Reforged (Download):
  Working Time: too much
  Status: On hold
  My most famous Minecraft mod (one out of a few).
• Game of Life:
  Working Time: ~1 hour
  Status: Done since Summer 2019 (Vacation project)
  Just another simple Game of Life, written in Processing.
• Sorting Visualizer:
  Working Time: ~5 hours
  Status: Done since August 2019
  Just another sorting visualizer with sound, written in Processing.
• UV Checker Map Generator:
  Working Time: ~20 minutes
  Status: Done since July 2021
  Generates a checkerboard pattern for texture atlas modelling, written in Processing.
• Some other leisure projects
• Many more to come, hopefully…

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Call is call.

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