The Department of Computer Science at the University of Cyprus cordially invites you to the Presentation entitled:

Security and Privacy issues in Online Social Networks

Speaker: Mr. Panagiotis Ilia
Affiliation: University of Crete, Greece
Category: Presentation
Location: Room 148, Faculty of Pure and Applied Sciences (FST-01), 1 University Avenue, 2109 Nicosia, Cyprus (directions)
Date: Monday, September 28, 2015
Time: 15:00-16:00 EET
Host: George Pallis ( and Eleni-Tatiani Synodinou (

Online social networks have radically transformed the online behavior and activities of users. Unfortunately, such services have also introduced a number of privacy issues, which have caught the attention of both the research community and data protection agencies. The implications of such privacy issues become alarming when considering the scale of adoption of these services and the abundance of personal information and data uploaded online. In certain cases, some users may not be concerned about privacy or may be unaware of the implications of their actions. Users may also not fully understand the complex access control mechanisms, and as a result, willingly disclose priv ate information without hesitation, oblivious to the true visibility of the uploaded content. Apart from privacy implications, the huge amount of users' data uploaded online can be leveraged by malicious users for launching various attacks, in order to compromise legitimate user accounts and gain unauthorized access. Here, at first, we demonstrate how a malicious user can compromise a user account with a very simple attack on Facebook's social authentication mechanism, and then, we redesign the social authentication mechanism for being resistant to such attacks. Also, we study the case of privacy leakage due to conflict of interests on social networks, with regards to the existing access control mechanisms for collective photos, and we design a simple and usable mechanism that allows each individual to control the disclosure of personal identifiable information.

Short Bio:
Panagiotis Ilia received his bachelor's degree in Informatics from the Aristotle University of Thessaloniki (Greece) in 2010 and his Master's degree in Advanced computing (Internet Technologies with Security) from the University of Bristol (UK) in 2012. Currently, he is enrolled as a PhD student at the University of Crete and as Research Assistant at the Distributed Computing Systems Laboratory (DCS), at the Foundation for Research and Technology – Hellas (FORTH). His research activities span into several areas of security and privacy in online social networks and distributed systems; from exploring practical attacks against online social networks and designing robust countermeasures, to designing cryptography-based multi-party access control mechanisms for decentralized systems.

The presentation is jointly organized by the Department of Computer Science at the University of Cyprus and the Department of Law at the University of Cyprus.

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