My research focuses on cryptographic primitives such as digital signatures and zero-knowledge proofs that strengthen user privacy while maintaining verifiability and auditability. Such schemes can be used as building blocks for protocols in the area of electronic voting and distributed digital payments systems such as blockchains. I am also a high school teacher enjoying to reveal the magic of Computer Science to young students.

Reach me at: firstname[0] || lastname at corelab.ntua.gr where || is concatenation

Publications

1. Panagiotis Grontas, Aris Pagourtzis, Marianna Spyrakou. Voting with coercion resistance and everlasting privacy using linkable ring signatures. Cryptology ePrint Archive, Paper 2025/002
2. George Papadoulis and Danai Balla and Panagiotis Grontas and Aris Pagourtzis. AQQUA: Augmenting Quisquis with Auditability. Cryptology ePrint Archive, Paper 2024/1181
3. Panagiotis Grontas, Aris Pagourtzis. Anonymity and everlasting privacy in electronic voting. Int. J. Inf. Secur. (2023). https://doi.org/10.1007/s10207-023-00666-2
4. Danai Balla, Pourandokht Behrouz, Panagiotis Grontas, Aris Pagourtzis, Marianna Spyrakou, Giannis Vrettos. Designated-verifier Linkable Ring Signatures with unconditional anonymity}, In 9th International Conference on Algebraic Informatics (CAI 2022). https://doi.org/10.1007/978-3-031-19685-0_5. Expanded version: Cryptology ePrint Archive Report 2022/1138
5. Pourandokht Behrouz, Panagiotis Grontas , Vangelis Konstantakatos, Aris Pagourtzis, and Marianna Spyrakou. Designated-Verifier Linkable Ring Signatures, Information Security and Cryptology - ICISC 2021 - 24th International Conference, Seoul, South Korea, December 1-3, 2021. Expanded version: Cryptology ePrint Archive Report 2022/470.
6. Panagiotis Grontas, Aris Pagourtzis, Alexandros Zacharakis, Bingsheng Zhang. Publicly Auditable Conditional Blind Signatures, Journal of Computer Security, vol. 29, no. 2, pp. 229-271, 2021.
7. Pourandokht Behrouz, Panagiotis Grontas, Marianna Spyrakou. On coercion resistance in decentralized voting (Extended Abstract), in 1st International Workshop on Foundations of Consensus and Distributed Ledgers, FOCODILE 2020, June 19, 2020
8. Panagiotis Grontas, Aris Pagourtzis, Alexandros Zacharakis. Security models for everlasting privacy. Fourth International Joint Conference on Electronic Voting (E-Vote-ID 2019). 1-4 October 2019, Lochau Bregenz, Austria, Taltech Press, pp.152-166. Expanded version: Cryptology ePrint Archive Report 2019/1193
9. Panagiotis Grontas, Aris Pagourtzis. (2019). Blockchain, consensus, and cryptography in electronic voting. Homo Virtualis, 2(1), 79-100. doi:http://dx.doi.org/10.12681/homvir.20289
10. Panagiotis Grontas, Aris Pagourtzis, Alexandros Zacharakis, Bingsheng Zhang. Towards Everlasting Privacy and Efficient Coercion Resistance in Remote Electronic Voting. In: Zohar A. et al. (eds) Financial Cryptography and Data Security. FC 2018. Lecture Notes in Computer Science, vol 10958. Springer, Berlin, Heidelberg. Cryptology ePrint Archive Report 2018/215
11. Panagiotis Grontas, Aris Pagourtzis, Alexandros Zacharakis. Coercion Resistance in a Practical Secret Voting Scheme for Large Scale Elections. 2017 14th International Symposium on Pervasive Systems, Algorithms and Networks & 2017 11th International Conference on Frontier of Computer Science and Technology & 2017 Third International Symposium of Creative Computing (ISPAN-FCST-ISCC), Exeter, 2017, pp. 514-519
12. Alexandros Zacharakis, Panagiotis Grontas, Aris Pagourtzis. Conditional Blind Signatures. In 7th International Conference on Algebraic Informatics (CAI 2017). Expanded version: Cryptology ePrint Archive Report 2017/682.
13. Panagiotis Grontas, Aris Pagourtzis, Efstathios Zachos. Computational Cryptography, Hellenic Academic Libraries, ISBN: 978-960-603-276-9, 2015.

Education

PhD, Privacy-Oriented Cryptographic Primitives and Protocols for Electronic Voting, National Technical University of Athens (2020)

MSc, Algorithms, Logic And Computation, University of Athens (2014)

MSc, Information Systems, Athens University of Economics and Business (2002)

BSc, Informatics, University of Piraeus (2000)