I am a postdoctoral researcher and software engineer at the Digital Security department of the Radboud University, interested in privacy enhancing technologies, cryptography, and in particular secure and privacy-friendly identity management. Before that my research involved the mathematical side of gauge theories and partial differential equations.


With an attribute-based credential scheme, you can selectively show some of your properties, while keeping others to yourself (more detailed explanation here). Idemix is an example of such a scheme; it is used in the IRMA project. Jaap-Henk Hoepman, Eric Verheul and myself have created a new, smart-card suitable attribute-based credential scheme.


Personal website: https://sietseringers.net/



PhD thesis

My PhD thesis Quantization using Jet Space Geometry and Identity Management using Credential Schemes, which I defended on 7 October 2016 at the University of Groningen, may be found here. I have many hardcopies left; if you would like one, feel free to contact me.



E. Verheul, S. Ringers, and J.-H. Hoepman. The self-blindable U-Prove scheme from FC’14 is forgeable. In Financial Cryptography 2016 (FC’16), to be published. PDF, slides

S. Ringers, J.-H. Hoepman, and W. Lueks. On linkability and malleability in self-blindable credentials. In The 9th WISTP International Conference on Information Security Theory and Practice (WISTP’2015), Heraklion, Crete, Greece, August 24-25 2015. PDF


Earlier publications

A. V. Kiselev and S. Ringers. A comparison of definitions for the Schouten bracket on jet spaces. In Proceedings of Sixth International Workshop “Group Analysis of Differential Equations and Integrable Systems”, Larnaca, Cyprus, 2012. arXiv: 1208.6196.

S. Ringers, Topologically Twisted Yang-Mills Theory on K3 Surfaces. MSc thesis, supervised by prof. R. Dijkgraaf. PDF.