Privacy and Accountability in Networks via Optimized Randomized Mix-nets

Panoramix is an H2020 project, where Tartu is one of the participants. See also here.

Objective of the project

The objective of the PANORAMIX project is the development of a multipurpose infrastructure for privacy-preserving communications based on ""mix-networks"" (mix-nets) and its integration into high-value applications that can be exploited by European businesses. Mix-nets protect not only the content of communications from third parties, but also obscure the exact identity of the senders or receivers of messages, through the use of cryptographic relays. Mix-nets are absolutely necessary for implementing strong privacy-preserving systems and protocols. This project directly aims to realize, integrate and demonstrate the use of a European infrastructure for mix-nets in the context of three diverse high-value applications that have clear, measurable, realistic, and achievable objectives. Our objectives are as follows. (Objective 1): Building a Mix-Net Infrastructure for Europe, by creating a European mix-network open-source codebase and infrastructure, (Objective 2): apply our infrastructure to private electronic voting protocols, where anonymity is necessary to guarantee ballot secrecy, and verifiability is needed for holding fair, transparent and trustworthy elections; (Objective 3): apply our infrastructure to privacy-aware cloud data-handling, in the context of privacy-friendly surveying, statistics and big data gathering protocols, where protecting the identity of the surveyed users is necessary to elicit truthful answers and incentivize participation; (Objective 4): apply our infrastructure to privacy-preserving messaging, where two or more users may communicate privately without third parties being able to track what is said or who-is-talking-to-whom. PANORAMIX facilitates a genuine collaboration between academia, civil society and industry bringing together a team of researchers from academia with a proven track record on privacy technologies and industry in domains where privacy technologies can have a very high impact.

Tartu

Our goals

Tartu is mostly active in WP3 ("Research"), especially in subtasks "construction of efficient zero-knowledge shuffles", "CRS vs RO model", and "decryption mixnets". We are also active in WP4, helping our partners in GRNET to implement our new research.

Team

  • Team leader: lead research fellow Helger Lipmaa
  • Toomas Krips, Michal Zajac, (expected to defend PhD in Summer 2018)
  • Behzad Abdolmaleki, Karim Baghery, Janno Siim (all started PhD studies in 2016)

Current MSc Students

  • Janno Veeorg

Alumni

  • Prastudy Fauzi (defended PhD in 2017, now a postdoc in Aarhus)
  • Annabell Kuldmaa (defended MSc in 2017)

Our publications within this project

  • Aggelos Kiayias, Annabell Kuldmaa, Helger Lipmaa, Janno Siim, Thomas Zacharias, "On the Security Properties of e-Voting Bulletin Boards". SCN 2018
  • 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.
  • 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.

Other dissemination

  • Event: E-enabled elections in Estonia: Forum on research and development in 2015, Tartu, Estonia, November 5-6th, 2015
    • Helger Lipmaa "Privacy and Accountability in Networks via Optimized Randomized Mixnets", introduced a concept of mixnets and Panoramix project in general to the audience of the meeting.
  • Event: The Summer Research Institute 2016 – Security/Privacy Edition (yearly summer school), EPFL, Lausanne, Switzerland, June 20-24th, 2016
    • Helger Lipmaa, "Cryptographically Secure Mix-Nets". Introduction of the concept of mix-nets and of the concrete papers later accepted to Asiacrypt 2016
  • Event: 6th Crypto.Sec Day, Athens, Greece, July 18th, 2016
    • Helger Lipmaa, "Cryptographically Secure Mix-Nets". Introduction of the concept of mix-nets and of the concrete papers later accepted to Asiacrypt 2016
  • Event: Estonian-Latvian theory days, 2016
    • Helger Lipmaa, "Cryptographically Secure Mix-Nets". Introduction of the concept of mix-nets and of the concrete papers later accepted to Asiacrypt 2016
  • Event: Asiacrypt 2016
    • Michal Zajac, "A Shuffle Argument Secure in the Generic Model". Conference presentation
  • Event: CiE 2017
    • Helger Lipmaa, "A Shuffle Argument Secure in the Generic Model"
  • Event: Estonian-Latvian Joint Theory Days 2017
    • Michal Zajac, "A Subversion-resistant SNARK"
    • Janno Siim, "An Efficient Pairing-Based Shuffle Argument"
  • Event: Asiacrypt 2017
    • Michal Zajac, "A Subversion-resistant SNARK"
    • Janno Siim, "An Efficient Pairing-Based Shuffle Argument"
  • Event: Number theory and coding theory: Contemporary applications in security
    • Helger Lipmaa, "ZK-SNARKs: foundations and applications"