Privacy-Enhancing Cryptography in Distributed Ledgers (PRIViLEDGE)

PRIViLEDGE is a H2020 EU project where Helger Lipmaa is the site leader of the University of Tartu.

  • However, University of Tartu withdrew from the project in 2019 due to Lipmaa's move to Simula UiB, Bergen*

Project overview

Blockchain and distributed ledger technologies (DLTs) have emerged as one of the most revolutionary developments in recent years, with the goal of eliminating centralised intermediaries and installing distributed trusted services. They facilitate trustworthy trades and exchanges over the Internet, power cryptocurrencies, ensure transparency for documents, and much more.

Although based on cryptographic techniques at their core, the currently deployed DLTs do not address privacy. Indeed, the very idea of a public ledger that stores a verifiable record of transactions at first appears inherently incompatible with the privacy requirements of many potential applications, which handle sensitive data such as trade secrets and personal information. New cryptographic techniques and protocols are therefore needed to protect the data, facilitate these applications, and make DLTs deliver on their promises.

PRIViLEDGE realises cryptographic protocols supporting privacy, anonymity, and efficient decentralised consensus for DLTs. In PRIViLEDGE, several European key players in cryptographic research and from the fintech and blockchain domains unite to push the limits of cryptographic protocols for privacy and security. Results from PRIViLEDGE are demonstrated through four ledger-based solutions: (1) verifiable online voting; (2) contract validation and execution for insurance; (3) university diploma record ledger; and (4) update mechanism for stake-based ledgers. The selected use cases are diverse and represent the principal application domains of DLT; this ensures wide reach and impact of the techniques developed in PRIViLEDGE beyond the immediate scope of the project.

Tartu

Our goals

Tartu is mostly active in WP2 (privacy-enhancing primitives) and WP3 (blockchain ). We have previous expertise in the area of SNARKs and decreasing trust model needed to construct them. In addition, we are interested in the use of blockchain as a trusted third party and in general in every connection between blockchain and privacy-enhancing cryptography.

Team

Postdocs

  • Toomas Krips (defended PhD in June 2019)

PhD students

  • Behzad Abdolmaleki, Karim Baghery, Janno Siim (all started PhD studies in 2016)
  • Zaira Pintado --- exchange PhD student from Universitat Pompeu Fabra, Barcelona (March 2019 -- June 2019)

Current MSc Students

  • Shahla Atapoor, Janno Veeorg

Alumni

  • Michal Zajac (now in Clearmatics - a blockchain company HQ-d in London)
  • Gennaro Avitabile --- Erasmus MSc exchange student from University of Salerno (September 2018 -- February 2019)
  • Hamid Khoshakhlagh --- currently PhD student in Aarhus (was PhD student in Tartu, September 2018 -- May 2019)

Publications

  • 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.
  • 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 ? of Lecture Notes in Computer Science, pages ?--?, 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 ? of Lecture Notes in Computer Science, pages ?--?, 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.
  • Atapoor, Shahla; Baghery, Karim (2019). Simulation Extractability in Groth’s zk-SNARK. In: Pérez-Solà C., Navarro-Arribas G., Biryukov A., Garcia-Alfaro J. (Ed.). Data Privacy Management, Cryptocurrencies and Blockchain Technology (336−354). Springer Nature Switzerland: Springer. (Lecture Notes in Computer Science).10.1007/978-3-030-31500-9_22.

Please also see our publications in the PANORAMIX project.

Eprints

Other dissemination

  • Event: Number theory and coding theory: Contemporary applications in security
    • Helger Lipmaa, "ZK-SNARKs: foundations and applications"
  • Presentation at Iran Telcommunication Reseach Center (ITRC), Tehran, http://itrc.ac.ir/
    • Karim Baghery, "The Bitcoin Lightning Network" (30.07.18)
  • Presentation at Sharif Blockchain Lab, Sharif University of Technology, Tehran, http://decentralab.ir/index-en.html
    • Karim Baghery, "Introduction to ZK proofs and SNARKs" (31.07.18)
  • Presentation at Information Systems and Security Lab (ISSL), Sharif University of Technology, Tehran, http://issl.sharif.ir/index.htm
    • Karim Baghery, "A Subversion-Resistant SNARK" (01.08.18)
  • Event: Joint Estonian-Latvian theory days
    • Janno Siim, "On the Security Properties of e-Voting Bulletin Boards"
    • Helger Lipmaa, "On QA-NIZK in the BPK model"
  • Presentation at Simula UiB, Bergen, Norway
    • Helger Lipmaa, "On QA-NIZK in the BPK model" (19.10.18)
  • Event: PENCIL - Workshop on Privacy ENhancing Cryptography In Ledgers
    • Behzad Abdolmaleki, "On QA-NIZK in the BPK model" (18.05.19)
  • Event: Joint Estonian-Latvian theory days
    • Helger Lipmaa: Zk-SNARKs: Foundations and Applications
    • Karim Baghery: On the Efficiency of Privacy-Preserving Smart Contract Systems
    • Shahla Atapoor: Simulation Extractability in Groth's zk-SNARK
    • Janno Siim: UC-Secure CRS Generation for SNARKs
    • Behzad Abdolmaleki: A Framework for UC-Secure Commitments from Publicly Computable Smooth Projective Hashing