Demetres Antoniades

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File sharing using peer-to-peer (p2p) systems is a major Internet application and the leading source of network traffic today. However, the dominance of p2p systems for file sharing has been recently challenged by an increasing number of services, such as RapidShare and MegaUpload, which offer users the ability to share files through centralized servers,(More)
Lack of trust is one of the main reasons for the limited cooperation between different organizations. The privacy of users is of paramount importance to administrators and organizations , which are reluctant to cooperate between each other and exchange network traffic traces. The main reasons behind reluctance to exchange monitored data are the protection(More)
Adobe Flash and Microsoft Silverlight are two widely adopted platforms for providing Rich Internet Applications (RIA) over the World Wide Web. The need for RIAs to retrieve content hosted on different domains, in order to enrich user experience, led to the use of cross-domain policies by content providers. Cross-domain policies define the list of RIA(More)
Short URLs have become ubiquitous. Especially popular within social networking services, short URLs have seen a significant increase in their usage over the past years, mostly due to Twitter's restriction of message length to 140 characters. In this paper, we provide a first characterization on the usage of short URLs. Specifically, our goal is to examine(More)
Antisocial Networks are distributed systems based on social networking Web sites that can be exploited by attackers, and directed to carry out network attacks. Malicious users are able to take control of the visitors of social sites by remotely manipulating their browsers through legitimate Web control functionality such as image-loading HTML tags,(More)
—Netflow is a protocol widely adopted by the security and performance measurements community. Nowadays, many distributed applications and architectures base their functionality on Netflow data collected at diverse environments. However, communities and administrators are reluctant to share exported Netflow data for privacy reasons. As a consequence, the(More)
Passive network monitoring is the basis for a multitude of systems that support the robust, efficient, and secure operation of modern computer networks. Emerging network monitoring applications are more demanding in terms of memory and CPU resources due to the increasingly complex analysis operations that are performed on the inspected traffic. At the same(More)
Network traces of Internet attacks are among the most valuable resources for network analysts and security researchers. However, organizations and researchers are usually reluctant to share their network data, as network packets may contain private or sensitive information. To alleviate the problem of information leakage, network traces are often anonymized(More)
—Complex networks often exhibit co-evolutionary dynamics, meaning that the network topology and the state of nodes or links are coupled, affecting each other in overlapping time scales. We focus on the co-evolutionary dynamics of online social networks, and on Twitter in particular. Monitoring the activity of thousands of Twitter users in real-time, and(More)