Weekly outline

  • Γενικά (Ακ. Έτος 2024 - 2025)

    Διδάσκοντες:

    • Στάθης Ζάχος, Καθηγητής (zachos@cs.ntua.gr)
    • Άρης Παγουρτζής, Καθηγητής (pagour@cs.ntua.gr)
    • Νίκος Λεονάρδος, Επίκ. Καθηγητής (nleon@cs.ntua.gr)
    • Παναγιώτης Γροντάς, Μεταδιδάκτορας (pgrontas@corelab.ntua.gr)


    Ημέρα και ώρα: Πέμπτη, 16:00-20:00 (Aίθουσα 1.1.31 - παλαιά κτίρια ηλεκτρολόγων)

    Έναρξη μαθημάτων: 20/2/2025 (το κυρίως μέρος ξεκινάει στις 13/3)

    Βασική βιβλιογραφία:



  • 1. Ηλεκτρονικές Ψηφοφορίες

    1. Το πρόβλημα των ηλεκτρονικών ψηφοφοριών
    2. Ιδιότητες ασφάλειας 
    3. Παραδοσιακά συστήματα εκλογών
    4. Επανάληψη σε κρυπτογραφικές κατασκευές σχετικές με ηλ. ψηφοφορίες
      • Ομομορφική Κρυπτογραφία
      • Σχήματα Δέσμευσης
      • Σ-πρωτόκολλα
      • Ισχυρός μετασχηματισμός Fiat-Shamir
      • Τυφλές Υπογραφές
      • Υπογραφές Προκαθορισμένου Επαληθευτή

    Διαφάνειες

    Προτεινόμενη Μελέτη

    • Bernhard, M. et al. (2017). Public Evidence from Secret Ballots. In: Krimmer, R., Volkamer, M., Braun Binder, N., Kersting, N., Pereira, O., Schürmann, C. (eds) Electronic Voting. E-Vote-ID 2017. Lecture Notes in Computer Science(), vol 10615. Springer, Cham. https://doi.org/10.1007/978-3-319-68687-5_6
    • Paillier, Pascal (1999). "Public-Key Cryptosystems Based on Composite Degree Residuosity Classes" (PDF). EUROCRYPT ’99.
    • Ivan Damgård, Mads Jurik: A Generalisation, a Simplification and Some Applications of Paillier's Probabilistic Public-Key System. Public Key Cryptography 2001: 119-136
    • Wojciech Jamroga: Pretty Good Strategies for Benaloh Challenge. E-Vote-ID 2023: 106-122
    • Schnorr, C. P. (1991). "Efficient signature generation by smart cards". Journal of Cryptology. 4 (3): 161–174. doi:10.1007/BF00196725. S2CID 10976365
    • Bernhard, Pereira, Warinschi (2012) How Not to Prove Yourself: Pitfalls of the Fiat-Shamir Heuristic and Applications to Helios. ASIACRYPT 2012
    • Mihir Bellare and Amit Sahai, Non-malleable encryption: Equivalence between two notions, and an indistinguishability-based characterization, CRYPTO’ 99
    • Jakobsson, M., Juels, A. (2000). Mix and Match: Secure Function Evaluation via Ciphertexts. In: Okamoto, T. (eds) Advances in Cryptology — ASIACRYPT 2000
    • Liu, J.K., Wei, V.K., Wong, D.S. (2004). Linkable Spontaneous Anonymous Group Signature for Ad Hoc Groups. In: Wang, H., Pieprzyk, J., Varadharajan, V. (eds) Information Security and Privacy. ACISP 2004. Lecture Notes in Computer Science, vol 3108. Springer, Berlin, Heidelberg. 
    • Cramer, R., Damgård, I., Schoenmakers, B. (1994). Proofs of Partial Knowledge and Simplified Design of Witness Hiding Protocols. In: Desmedt, Y.G. (eds) Advances in Cryptology — CRYPTO ’94. CRYPTO 1994. Lecture Notes in Computer Science, vol 839. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-48658-5_19
    • Markus Jakobsson, Kazue Sako, and Russell Impagliazzo. “Designated Verifier Proofs and Their Applications”. In: EUROCRYPT ’96

    • 2. Ηλεκτρονικές Ψηφοφορίες

      • Mixnets και Verifiable Mixnets, Επίθεση tagging
      • Bayer Groth Proof of Shuffle
      • Helios: Τυπικός ορισμός λειτουργιών και επιθέσεις λόγω wFS
      • Παραλλαγές Helios για everlasting privacy
      • Παραλλαγές Helios για receipt - freeness και participation privacy 
      • Eligibility Verifiability και Belenios

      Διαφάνειες

      Προτεινόμενη Μελέτη

      • Pfitzmann, B.: Breaking an efficient anonymous channel. In: EUROCRYPT’94. pp. 332–340 (1995)
      • Bayer, S., Groth, J. (2012). Efficient Zero-Knowledge Argument for Correctness of a Shuffle–EUROCRYPT 2012
      • Βen Adida. 2008. Helios: web-based open-audit voting. In Proceedings of the 17th conference on Security symposium (SS'08). USENIX Association, USA, 335–348.
      • Haines, T., Mueller, J., Mosaheb, R., & Pryvalov, I. (2023). SoK: Secure E-Voting with Everlasting Privacy. In Proceedings on Privacy Enhancing Technologies (PoPETs).
      • Grontas, P., Pagourtzis, A. Anonymity and everlasting privacy in electronic voting. Int. J. Inf. Secur. 22, 819–832 (2023). 
      • Denise Demirel, J Van De Graaf, and R Araújo. “Improving Helios with Everlasting Privacy Towards the Public”. In: EVT/WOTE’12 Proceedings of the 2012 international conference on Electronic Voting Technology/Workshop on Trustworthy Elections (2012).
      • Josh Benaloh and Dwight Tuinstra. “Receipt-free secret-ballot elections (extended abstract)”. In: Proceedings of the twenty-sixth annual ACM symposium on Theory of computing - STOC ’94. ACM Press, 1994, pages 544– 553.
      • Martin Hirt and Kazue Sako. “Efficient receipt-free voting based on homomorphic encryption”. In. EUROCRYPT 2000
      • Belenios: A Simple Private and Verifiable Electronic Voting System. Véronique Cortier, Pierrick Gaudry, and Stéphane Glondu. In Foundations of Security, Protocols, and Equational Reasoning, pp. 214-238, 2019
      • Kulyk, O., Teague, V., Volkamer, M. Extending Helios Towards Private Eligibility Verifiability. Vote-ID 2015.
      • Pyrros Chaidos, Véronique Cortier, Georg Fuchsbauer, and David Galindo. BeleniosRF: A non-interactive receipt-free electronic voting scheme. In 23rd ACM Conference on Computer and Communications Security (CCS’16), pages 1614–1625, Vienna, Austria, 2016
      • Olivier Blazy, Georg Fuchsbauer, David Pointcheval, and Damien Vergnaud. Signatures on randomizable ciphertexts. In Public Key Cryptography - PKC 2011

      • 3. Ηλεκτρονικές Ψηφοφορίες

        • Voting with Blind Signatures
        • Voting with Ring Signatures
        • Decentralised Voting - Open Vote Network
        • Voting on the blockchain

        Διαφάνειες

        Προτεινόμενη Μελέτη

        • Fujioko A, Okamoto T, Ohta T (1992) A practical secret voting scheme for large-scale elections. In: Proceedings of advances in cryptology, AUSCRYPT’92, Springer, pp 244–260
        • Joseph K. Liu, Victor K. Wei, and Duncan S. Wong. “Linkable Spontaneous Anonymous Group Signature for Ad Hoc Groups (Extended Abstract)”. In: ACISP 2004. Vol. 3108. LNCS. 2004, pp. 325–335. doi: 10. 1007/978-3-540-27800-9_28
        • Hao, Feng, Peter Y. A. Ryan and Piotr Zielinski. “Anonymous voting by two-round public discussion.” IET Inf. Secur. 4 (2010): 62-67.
        • Patrick McCorry, Siamak Shahandashti, and Feng Hao, A smart contract for boardroom voting with maximum voter privacy, pp. 357–375, 01 2017.
        • Μohamed Seifelnasr, Hisham S. Galal, and Amr M. Youssef. 2020. Scalable Open-Vote Network on Ethereum. In Financial Cryptography and Data Security: FC 2020 International Workshops, AsiaUSEC, CoDeFi, VOTING, and WTSC.

        • 4. Ηλεκτρονικές Ψηφοφορίες

          • Coercion Resistance: JCJ/Civitas και βελτιώσεις.
          • Τυπικοί Ορισμοί Verifiability.
          • Τυπικοί Ορισμοί Privacy: BPRIV.
          • Απόδειξη ότι το Helios διαθέτει weak verifiability.
          • Απόδειξη ότι το Belenios διαθέτει strong verifiability.
          • Απόδειξη ότι το Helios διαθέτει ballot privacy.

          Διαφάνειες

          Προτεινόμενη Μελέτη:

          • A. Juels, D. Catalano, and M. Jakobsson, “Coercion-resistant electronic elections,” in Proceedings of the 2005 ACM Workshop on Privacy in the Electronic Society, WPES, 2005
          • Warren D. Smith. “New cryptographic voting scheme with best-known theoretical properties”. In: Frontiers in Electronic Elections. 2005.
          • J. Clark and U. Hengartner, “Selections: Internet Voting with Over-the Shoulder Coercion-Resistance,” in FC 2011.
          • Roberto Araújo, Sébastien Foulle, and Jacques Traoré. “A practical and secure coercion resistant scheme for remote elections”. In: Frontiers of Electronic Voting. 2007 
          • Steve Kremer, Mark Ryan, and Ben Smyth. “Election Verifiability in Electronic Voting Protocols”. In: ESORICS 2010.
          • Cortier, V., Galindo, D., Glondu, S., Izabachène, M. (2014). Election Verifiability for Helios under Weaker Trust Assumptions. ESORICS 2014.
          • Véronique Cortier and Ben Smyth, Attacking and fixing helios: An analysis of ballot secrecy, J. Comput. Secur. (2013), 89–148.
          • David Bernhard, Véronique Cortier, David Galindo, Olivier Pereira, and Bogdan Warinschi, Sok: A comprehensive analysis of game-based ballot privacy definitions, 2015 IEEE Symposium on Security and Privacy, 2015, pp. 499–516.

          • Blockchain & Consensus I

            • Εισαγωγή σε Blockchain & Bitcoin.
            • Περιγραφή του αλγορίθμου του Bitcoin backbone.
            • Ορισμός των ιδιοτήτων common prefix, chain quality, chain growth. 
            • Selfish mining.
            • Αποδείξεις ασφάλειας του Bitcoin backbone.


            Διαφάνειες

            Το μάθημα θα βασιστεί στη δημοσίευση: GKL.

            Άλλες πηγές: