Colloquia and Seminars

To join the email distribution list of the cs colloquia, please visit the list subscription page.


Computer Science events calendar in HTTP ICS format for of Google calendars, and for Outlook.

Academic Calendar at Technion site.

Upcoming Colloquia & Seminars

  • Theory Seminar: Weak Zero-Knowledge Beyond the Black-Box Barrier

    Speaker:
    Omer Paneth (MIT)
    Date:
    Wednesday, 23.1.2019, 12:30
    Place:
    Taub 201

    The round complexity of zero-knowledge protocols is a long-standing open question, yet to be settled under standard assumptions. So far, the question has appeared equally challenging for relaxations such as weak zero-knowledge and witness hiding. Protocols satisfying these relaxed notions under standard assumptions have at least four messages, just like full-fledged zero knowledge. The difficulty in improving round complexity stems from a fundamental barrier: none of these notions can be achieved in three messages via reductions (or simulators) that treat the verifier as a black box.

    We introduce a new non-black-box technique and use it to obtain the first protocols that cross this barrier under standard assumptions. Our main results are:
    – Weak zero-knowledge for NP in two messages, assuming quasipolynomially-secure fully-homomorphic encryption and other standard primitives (known from quasipolynomial hardness of Learning with Errors), as well as subexponentially-secure one-way functions.
    – Weak zero-knowledge for NP in three messages under standard polynomial assumptions (following for example from fully-homomorphic encryption and factoring).

    We also give, under polynomial assumptions, a two-message witness-hiding protocol for any language L \in NP that has a witness encryption scheme. This protocol is also publicly verifiable.

    Our technique is based on a new homomorphic trapdoor paradigm, which can be seen as a non-black-box analog of the classic Feige-Lapidot-Shamir trapdoor paradigm.

    Joint work with Nir Bitansky and Dakshita Khurana

  • Learning Word Relatedness over Time

    Speaker:
    Guy Rosin, M.Sc. Thesis Seminar
    Date:
    Sunday, 27.1.2019, 15:00
    Place:
    Taub 601
    Advisor:
    Dr. K. Radinsky and Prof. S. Markovitch

    Search systems are often focused on providing relevant results for the "now", assuming both corpora and user needs that focus on the present. However, many corpora today reflect significant longitudinal collections ranging from 20 years of the Web to hundreds of years of digitized newspapers and books. Understanding the temporal intent of the user and retrieving the most relevant historical content has become a significant challenge. Common search features, such as query expansion, leverage the relationship between terms but cannot function well across all times when relationships vary temporally. In this work, we introduce a temporal relationship model that is extracted from longitudinal data collections. The model supports the task of identifying, given two words, when they relate to each other. We present an algorithmic framework for this task and show its application for the task of query expansion, achieving high gain.

  • Applying Machine Learning for Identifying Attacks at Run-time

    Speaker:
    Nurit Devir, M.Sc. Thesis Seminar
    Date:
    Monday, 28.1.2019, 10:00
    Place:
    Taub 601
    Advisor:
    Prof. O. Grumberg and Prof. S. Markovitch

    With the increase in malicious activity over the Internet, it has become extremely important to build tools for automatic detection of such activity. There have been attempts to use machine learning to detect network attacks, but the difficulty in obtaining positive (attack) examples, led to using one-class methods for anomaly detection. In this work we present a novel framework for using multiclass learning to induce an attack detector that identifies attacks at run time. We designed a network simulator that is used to produce network activity. The simulator includes an attacker that stochastically violates the normal activity, yielding positive as well as negative examples. We have also designed a set of features that withstand changes in the network topology. Given the set of tagged feature vectors, we can then apply a learning algorithm to produce a multiclass attack detector. Our framework allows the user to define a cost matrix for specifying the cost for each type of detection error (predicting some value for a run, when its real tag is another value). We tested our framework in a wide variety of network topologies and in different setups, including transfer learning and dynamic networks. In addition, we also referred to how to choose the router(s) that will act as monitor(s) and predict the label of a run. The presented framework will enable any organization to defend itself with an attack detector that is automatically adapted to its particular setting. Please note: the seminar will be given in Hebrew.

  • Understanding Reader Backtracking Behavior in Online News Articles

    Speaker:
    Uzi Smadja, M.Sc. Thesis Seminar
    Date:
    Tuesday, 29.1.2019, 12:30
    Place:
    Taub 401
    Advisor:
    Prof. M. Naaman & Prof. S. Markovitch

    Rich engagement data can shed light on how people interact with online content and how such interactions may be determined by the content of the page. In this work, we investigate a specific type of interaction, backtracking, which refers to the action of scrolling back in a browser while reading an online news article. We leverage a dataset of close to 700K instances of more than 15K readers interacting with online news articles, in order to characterize and predict backtracking behavior. We first define different types of backtracking actions. We then show that "full" backtracks, where the readers eventually return to the spot at which they left the text, can be predicted by using features that have been shown to relate to text readability. This finding highlights the relationship between backtracking and readability and suggests that backtracking could help assess readability of content at scale.

  • CYBERDAY 2019

    CYBERDAY 2019

    Date:
    Tuesday, 12.3.2019, 09:30
    Place:
    Technion

    CYBERDAY 2019 event, organized by Prof. Eli Biham, Prof. Sara Bitan, and the Technion Hiroshi Fujiwara Cyber Security Research Center, will be held on Tuesday, March 12, 2019 at the Technion,

    Keynote speakers:
    Prof. Bart Preneel (KU Leuven, Belgium)
    Prof. Adi Shamir (The Weizmann Institute of Science).

    Most of the lectures will be given in Hebrew and a poster session will take place at the brea: graduate students and all who are interested to present their research should contact cyber at technion.ac.il as soon as possible by February 28, following the instructions in the event site.

    More Information, full program (to be updated shortly) and (free be required) registration.

    Hope to see you there.