Cryptographic Protocols research group
Group Description
The research group performs research in the generic area of cryptographic protocols, including but not only
- Design of efficient zero-knowledge protocols
- E-voting, esp. including
- Verifiable (zero-knowledge) mixnets
- Bulletin boards
- Blockchain, esp. privacy in blockchain
- Privacy-preserving data mining and machine learning
- Relations with coding theory
The group is currently or has been recently funded by the following projects:
- Panoramix - H2020 project on verifiable mixnets (finished in January, 2019)
- PRIViLEDGE - H2020 project on privacy in distributed ledgers (will finish in Fall, 2019)
- PRG49 - Estonian research grant on "Cryptographic Protocols and Coding Theory"
Please see the individual project places for more information about our research.
Team
- Team leader: research professor Helger Lipmaa (dblp)
- Moved to Simula UiB from August 1, 2019; currently continuing to work with 20%
- Senior researchers
- Ph.D. students:
- M.Sc. students:
Alumni (not complete)
- Sven Laur (defended PhD in 2008, now a senior research fellow in Tartu)
- Bingsheng Zhang (defended PhD in 2011, now a professor at Zhejiang University, China)
- Prastudy Fauzi (defended PhD in 2017, now a postdoc in Aarhus)
- Rafik Chaabouni (defended PhD in 2017, now a IT risk analyst, Pictet Group)
- Michal Zajac (dblp) (now at Clearmatics, London-based blockchain company)
- Gennaro Avitabile (Erasmus exchange student from Salerno, Italy, 01.09.18 -- 14.02.18)
- Hamidreza Khoshakhlagh (Ph.D. student 01.09.18 - 31.05.19, now a PhD student in Aarhus)
- Zaira Pindado (visiting PhD student, 01.04.19 - 18.06.19)
- Janno Veeorg (MSc student, -31.07.19)
- Shahla Atapoor (Msc student, -31.08.19)
- Toomas Krips (dblp, -31.08.19, now a postdoc in Stuttgart)
Recent Publications
2016
- Prastudy Fauzi, Helger Lipmaa and Michał Zając. A Shuffle Argument Secure in the Generic Model. In Jung Hee Cheon and Tsuyoshi Takagi, editors, ASIACRYPT 2016, volume ? of Lecture Notes in Computer Science, pages 841--872, Hanoi, Vietnam, December 4--8, 2016. Springer, Heidelberg.
- Helger Lipmaa. Prover-Efficient Commit-And-Prove Zero-Knowledge SNARKs. In David Pointcheval, Abderrahmane Nitaj and Tajjeeddine Rachidi, editors, Africacrypt 2016, volume 10032 of Lecture Notes in Computer Science, pages 200--216, Fes, Morocco, April 13--15, 2016. Springer, Heidelberg. Invited to IJACT as one of the three best papers
- Prastudy Fauzi and Helger Lipmaa. Efficient Culpably Sound NIZK Shuffle Argument without Random Oracles. In Kazue Sako, editor, CT-RSA 2016, volume 9610 of Lecture Notes in Computer Science, pages 200--216, San Franscisco, CA, USA, February 29--March 4, 2016. Springer, Heidelberg.
2017
- Helger Lipmaa. Prover-efficient commit-and-prove zero-knowledge SNARKs. International Journal of Applied Cryptography (IJACT), Vol. 3, No. 4, 2017. This is an invited journal version of the earlier Africacrypt 2016 paper
- Behzad Abdolmaleki, Karim Baghery, Helger Lipmaa and Michal Zajac. A Subversion-Resistant SNARK. In Thomas Peyrin and Tsuyoshi Takagi, editors, ASIACRYPT (3) 2017, volume 10626 of Lecture Notes in Computer Science, pages 3--33, Hong Kong, China, December 3--7, 2017. Springer, Heidelberg. Invited to Journal of Cryptology as one of the three best papers
- Prastudy Fauzi, Helger Lipmaa, Janno Siim and Michal Zajac. An Efficient Pairing-Based Shuffle Argument. In Thomas Peyrin and Tsuyoshi Takagi, editors, ASIACRYPT (2) 2017, volume 10625 of Lecture Notes in Computer Science, pages 97--127, Hong Kong, China, December 3--7, 2017. Springer, Cham.
- Helger Lipmaa and Kateryna Pavlyk. A Simpler Rate-Optimal CPIR Protocol. In Aggelos Kiayias, editor, FC 2017, volume ? of Lecture Notes in Computer Science, pages ?--?, Malta, April 3--7, 2017. Springer, Heidelberg. Accepted.
- Helger Lipmaa. Optimally Sound Sigma Protocols Under DCRA. In Aggelos Kiayias, editor, FC 2017, volume ? of Lecture Notes in Computer Science, pages ?--?, Malta, April 3--7, 2017. Springer, Heidelberg. Accepted.
- Florian Bourse, Fabrice Benhamouda and Helger Lipmaa. CCA-Secure Inner-Product Functional Encryption from Projective Hash Functions. In Serge Fehr, editor, PKC 2017, volume 10175 of Lecture Notes in Computer Science, pages 36--66, Amsterdam, Netherlands, March 28--31, 2017. Springer, Heidelberg.
2018
- Aggelos Kiayias, Annabell Kuldmaa, Helger Lipmaa, Janno Siim and Thomas Zacharias. On the Security Properties of e-Voting Bulletin Boards. In Dario Catalano and Roberto de Prisco, editors, SCN 2018, volume 11035 of Lecture Notes in Computer Science, pages 505--523, Amalfi, Italy, September 5--7, 2018. Springer, Cham.
- Sven Heiberg, Ivo Kubjas, Janno Siim and Jan Willemson. On Trade-offs of Applying Block Chains for Electronic Voting Bulletin Boards. In Proceedings of the Third International Joint Conference on Electronic Voting E-Vote-ID 2018, 2–5 October 2018, Lochau/Bregenz, Austria, TUT press, pp. 259-276. Available at http://eprint.iacr.org/2018/685
2019
- Behzad Abdolmaleki, Karim Baghery, Helger Lipmaa, Janno Siim and Michal Zajac. DL-Extractable UC-Commitment Schemes. In Robert Deng and Moti Yung, editors, ACNS 2019, volume 11464 of Lecture Notes in Computer Science, pages 385--405, Bogotá , Colombia, June 5--7, 2019. Springer, Heidelberg. eprint version
- Behzad Abdolmaleki, Karim Baghery, Helger Lipmaa, Janno Siim and Michal Zajac. UC-Secure CRS Generation for SNARKs. In Johannes Buchmann, Abderrahmane Nitaj and Tajjeeddine Rachidi, editors, Africacrypt 2019, volume 11627 of Lecture Notes in Computer Science, pages 99--117, Rabat, Morocco, July 9--11, 2019. Springer, Heidelberg.
- Karim Baghery. On the Efficiency of Privacy-Preserving Smart Contract Systems. In Johannes Buchmann, Abderrahmane Nitaj and Tajjeeddine Rachidi, editors, Africacrypt 2019, volume ? of Lecture Notes in Computer Science, pages ?--?, Rabat, Morocco, July 9--11, 2019. Springer, Heidelberg.
- Shahla Atapoor and Karim Baghery. Simulation Extractability in Groth's zk-SNARK. CBT 2019, September 26-27, 2019, University of Luxembourg, Luxembourg.
- Behzad Abdolmaleki and Daniel Slamanig. A Framework for UC-Secure Commitments from Publicly Computable Smooth Projective Hashing. IMA CC 2019.
- Karim Baghery. Subversion-Resistant Simulation (Knowledge) Sound NIZKs. IMA CC 2019.
2020
- Janno Siim, Prastudy Fauzi, Michał Zając, Panos Louridas, Foteinos Mergoupis-Anagnou, Georgios Korfiatis, and Antonis Aggelakis. A Non-Interactive Shuffle Argument With Low Trust Assumptions. Accepted to CT-RSA 2020
- Behzad Abdolmaleki, Helger Lipmaa, Janno Siim and Michał Zając. On QA-NIZK in the BPK model. In Aggelos Kiayias, Markulf Kohlweiss, Petros Wallden, and Vassilis Zikas, editors, PKC (1) 2020, volume 12110 of Lecture Notes in Computer Science, pages 590--620, Edinburgh, UK, May 4--7, 2020. Springer, Cham. https://link.springer.com/chapter/10.1007%2F978-3-030-45374-9_20
- Helger Lipmaa. Key-and-Argument-Updatable QA-NIZKs. In Vladimir Kolesnikov, editor, SCN 2020, volume ? of Lecture Notes in Computer Science, pages ?--?, Amalfi, Italy, September 14--16, 2020. Springer, Cham.
- Behzad Abdolmaleki and Sebastian Ramacher and Daniel Slamanig. Lift-and-Shift: Obtaining Simulation Extractable Subversion and Updatable SNARKs Generically. Accepted to ACM CCS 2020.