Leiden Encrypted Data Processing Group

The LEDaP group, led by Eleftheria Makri, is the research group of LIACS focusing on Secure Computation technologies. We study, develop and enhance different types of technologies that allow computing on encrypted data, such as Multiparty Computation, Homomorphic Encryption, Function Secret Sharing etc. We have a broad interest in Privacy Enhancing Technologies, and we research both theory and applications of secure computation. In particular, we currently investigate Privacy-Preserving Machine Learning, as it is an imminent application scenario.































People

       





































Publications

Book Chapters

  1. Q. Ma, E. Makri, N. Zidaric. "PriFT: Private Fine-Tuning on a Real Use Case". In: Artificial Intelligence and Security: Recent Developments, to appear, 2026.

Journals

  1. C. Bonte, E. Makri, A. Ardeshirdavani, J. Simm, Y. Moreau, F. Vercauteren. "Towards Practical Privacy-Preserving Genome-Wide Association Study". In BMC Bioinformatics, 19(1), 1-12, 2018.
  2. E. Makri, J. ten Brinke, R. Evers, P. Man, H. Olthof. "Privacy-Friendly Wi-Fi-Based Occupancy Estimation with Minimal Resources". In International Journal of Ambient Computing and Intelligence (IJACI), 9(4), 34-51, 2018.
  3. E. Makri and E. Konstantinou. "Constant Round Group Key Agreement Protocols: A Comparative Study". In Computers & Security, 30(8), 643-678, 2011.

Conferences and Workshops

  1. K. Baghery, E. Makri, D. K. Suryakari. "Packed Pre-Constructed PVSS for Randomness Generation and E-Voting". In International Conference on Security and Cryptography for Networks, to appear. 2026.
  2. C. Delpech de Saint Guilhem, E. Makri, D. Rotaru, T. Tanguy. "The return of Eratosthenes: Secure Generation of RSA Moduli using Distributed Sieving". In ACM SIGSAC Conference on Computer and Communications Security, pp. 594-609. 2021.
  3. E. Makri, T. Wood. "Full-Threshold Actively-Secure Multiparty Arithmetic Circuit Garbling". In International Conference on Cryptology and Information Security in Latin America, pp. 407-430. Springer, Cham, 2021.
  4. E. Makri, D. Rotaru, F. Vercauteren, S. Wagh. "Rabbit: Efficient Comparison for Secure Multi-Party Computation". In International Conference on Financial Cryptography and Data Security, pp. 249-270. Springer, Berlin, Heidelberg, 2021.
  5. E. Makri, D. Rotaru, N. P. Smart, F. Vercauteren. "EPIC: Efficient Private Image Classification (or: Learning from the Masters)". In Cryptographers' Track at the RSA Conference, pp. 473-492. Springer, Cham, 2019.
  6. E. Makri, M. H. Everts, S. de Hoogh, A. Peter, H. op den Akker, P. H. Hartel, W. Jonker. "Privacy-Preserving Verification of Clinical Research". In GI Sicherheit 2014, Lecture Notes in Informatics, S. Katzenbeisser, V. Lotz, and E. Weippl (eds.), pp. 481-500, 2014.

Preprints

  1. S. Sun, E. Makri. "SoK: Multiparty Computation in the Preprocessing Model". In IACR Cryptology ePrint Archive, 2025, 060.























Teaching


Capture the Flag: Cybersecurity in Practice

   

This is a full-year extracurricular course, where students work on a real-world hacking challenge in groups of 3-6 participants. During the fall semester we have bi-weekly lectures to familiarize with the basics of hacking techniques and bi-weekly meet-ups where we are trying to solve CTF challenges. In the spring semester the meet-ups continue with a focus on the final big challenge, and there are a few guest lectures as well. From the beginning of the course and for the duration of the whole year, students receive a real-world hacking challenge/target on which they aim to identify vulnerabilities together with their teammates. We do this always in an ethical manner, following responsible disclosure principles, which are explained at the beginning of the course.



Rings and Finite Fields in Modern Cryptography

   

This is an ASCI graduate school course, which treats selected topics from symmetric and public-key cryptography, as well as advanced cryptographic primitives, together with efficient implementation techniques for modern (distributed) systems combining CPUs, GPUs, and FPGAs. The goal is to give students an understanding of the cryptographic notions and the underlying mathematical structures, and enable them to observe and recognize how mathematical parameter choices and targeted implementation technology affect the performance of the system, thus developing an intuition for good trade-offs between sufficient cryptographic strength and implementation efficiency.


Security

           

This course is part of all Computer Science related Bachelor programmes offered by LIACS. It is a second year introductory course that aims at familiarizing students with the different facets of Information Security. The basic information security principles, goals, and requirements are introduced and explained. The students investigate the main pitfalls in system and software design (so-called vulnerabilities), as well as the ways to ensure security (defenses), and they get a taste of various security aspects, from cryptographic techniques to organizational security. Moreover, students get a chance to practice with hands-on assignments, which enhances their experience of the course, and makes the content tangible.


Cyber Security Management

               

This course is part of the Master's programme ICT in Business and the Public Sector. It is not a technical course, but it rather aims at providing a broad managerial insight on ICT Security and the deployment thereof at a large organization. The students learn from hands-on ICT specialists how attacks work, what are plausible defenses against attacks, and how new IT trends, such as the Internet of Things, affect the security landscape. They also learn how the human factor plays a crucial role in security, what other ethical and legal considerations should be accounted for, as well as potential career paths for their own future.


Integration Course: Online Deception

This course is part of the Cybersecurity & Cybercrime minor programme. The students explore the problem of online deception from a multidisciplinary approach, with a special focus on impersonation. Impersonation refers to a type of deception whereby an actor uses another person’s identity for malicious purposes. In the online environment, impersonation is expressed through several types of cyber attacks, each of which can lead to social, economic, and political harm for individuals and organizations. The main objective of this course is to prepare students to understand and critically address the complex and multifaceted problem of online impersonation from a variety of disciplines, drawing on insights from computer science, criminology, law and governance.















Student Supervision

Master's Thesis Supervision

Master's Thesis Co-Supervision

Bachelor Thesis Supervision

Bachelor Thesis Co-Supervision