Cybersecurity Seminars

The seminar features presentations of current topics within the interdisciplinary field of cybersecurity.

We would like to thank all presenters and participants for making this seminar a success.

Presentations in Fall 2015:

Presentations take place on a biweekly schedule on Wednesdays at 11am.
  • Wednesday, September 2, 2015, 11am in SE 215:
    Constant-round multiparty computation with fairness and guarantee of output delivery
    Presenter: Feng-Hao Liu, Florida Atlantic University, Computer & Electrical Engineering and Computer Science
  • Abstract:
    We study the round complexity of multiparty computation with fairness and guaranteed output delivery, assuming existence of an honest majority. We demonstrate a new lower bound and a matching upper bound. Our lower bound rules out any two-round fair protocols in the standalone model, even when the parties are given access to a common reference string (CRS). The lower bound follows by a reduction to the impossibility result of virtual black box obfuscation of arbitrary circuits. Then we demonstrate a three-round protocol with guarantee of output delivery, which in general is harder than achieving fairness (since the latter allows the adversary to force a fair abort). We develop a new construction of a threshold fully homomorphic encryption scheme, with a new property that we call "flexible" ciphertexts. Roughly, our threshold encryption scheme allows parties to adapt flexible ciphertexts to the public keys of the non-aborting parties, which provides a way of handling aborts without adding any communication. This is a joint work with S. Dov Gordon (George Mason University) and Elaine Shi (Cornell University)
  • Wednesday, September 16, 2015, 11am in SE 215:
    A framework for biometric visual cryptography
    Presenter: Angela Robinson, Florida Atlantic University, Mathematical Sciences
  • Abstract:
    Visual cryptography is an increasingly popular cryptographic technique which allows for secret sharing and encryption of sensitive data. This method has been extended and applied to secure biometric data in various protocols. We propose a general framework to help assess the security of these extended biometric visual cryptographic schemes (e-BVC). We formalize the security of e-BVC schemes with respect to indistinguishability and irreversability notions. Based on our definitions, we present theoretical analysis of e-BVC schemes and propose non-trivial attacks. We show that our framework can be applied to derive quantitative security analysis of e-BVC schemes. As an application, we present a case analysis for a recent implementation of a face recognition protocol and argue that the scheme is not secure with respect to our definitions. We discuss the practical impact of our attacks in detail. This is a joint work with Koray Karabina (Florida Atlantic University).
  • Wednesday, September 30, 2015, 11am in EE 405:
    From Rational to Social and Socio-Rational Secret Sharing Schemes
    Presenter: Mehrdad Nojoumian, Florida Atlantic University, Computer & Electrical Engineering and Computer Science
  • Abstract:
    Secret Sharing is widely used in distributed secure systems as a cryptographic primitive. In this scheme, a secret is divided into shares to be distributed among a set of players. An authorized subset of players can then cooperate to recover the secret. In this talk, we initially review Shamir's secret sharing as well as rational secret sharing (RSS) schemes. Subsequently, the notion of social secret sharing (SSS) is introduced in which shares are allocated based on a player's reputation and the way she interacts with other parties. In other words, this scheme renews shares at each cycle without changing the secret and allows the trusted parties to gain more authority. Finally, the concept of socio-rational secret sharing (SRS) is introduced in which rational foresighted players have long-term interactions in a social context, that is, players run secret sharing while founding and sustaining a trust network. We show how this social reinforcement stimulates players to be cooperative.
  • Wednesday, October 14, 2015, 11am in SE 215:
    Cryptanalysis of a modern rotor machine in a multicast setting
    Presenter: Shane Kepley, Florida Atlantic University, Mathematical Sciences
  • Abstract:
    At FSE '93, Ross Anderson presented a modern byte-oriented rotor machine that is suitable for fast software implementation. The rotor machine combines clever use of a linear feedback shift register along with an enigma-style permutation for fast encryption that is resistant to naive linear algebra attacks on LFSRs. Using a combination of chosen ciphertexts and chosen plaintexts, we show that in a setting with at least four recipients, a more sophisticated linear algebra attack is still feasible and the recovery of an (equivalent) secret key can be found in minutes on a typical computer. This is joint work with David Russo and Rainer Steinwandt.

Presentations in Spring 2013:

  • Thursday, February 7, 2013, 3 pm in SE 215:
    Scalable deniable group key establishment
    Presenter: Adriana Suárez Corona, FAU Mathematical Sciences
  • Thursday, February 21, 2013, 3 pm in SE 215:
    Identity based signature schemes by using pairings
    Presenter: Parshuram Budhathoki, FAU Mathematical Sciences
  • Thursday, March 21, 2013, 3 pm in SE 215:
    Group factorization and cryptography
    Presenter: Tran van Trung, University of Duisburg-Essen, Germany
  • Thursday, April 4, 2013, 3 pm in SE 215:
    Information Redaction in a Social Enterprise
    Presenter: Saeed Rajput, Nova Southeastern University

Presentations in Spring 2012:

  • Thursday, January 19, 2pm in SE 215:
    Mathematics in cryptographic key exchange: Alice, Bob, and Carol need to talk
    Presenter: Rainer Steinwandt, FAU Mathematical Sciences
  • Thursday, February 2, 2pm in EE405:
    Designing Secure Architectures using Security Patterns
    Presenter: Eduardo Fernandez, FAU Computer Science & Engineering
  • Thursday, February 16, 2pm in SE 215:
    Private Geo-Social Networks
    Presenter: Bogdan Carbunar, FIU School of Computing and Information Sciences
  • Thursday, March 1, 2pm in SE215:
    Economics of Information Security
    Presenter: Derrick Huang, FAU Information Technology and Operations Management
  • Thursday, March 22, 2pm in SE215:
    Non-Abelian Cryptography
    Presenter: Spyros Magliveras, FAU Mathematical Sciences
  • Monday, April 2, 3:15pm in SE 215:
    Lightweight Side-Channel Countermeasures
    Presenter: Axel Poschmann, Nanyang Technological University
  • Thursday, April 5, 2pm in SE 215:
    Application Defense
    Presenter: Saeed Rajput, Nova Southeastern University
  • Thursday, April 19, 2pm in SE 215:
    Group key establishment: adding perfect forward secrecy at the cost of one round
    Presenter: Adriana Suárez Corona, Universidad de Oviedo
For questions or comments on the seminar please contact Adriana Suárez Corona.