Remote Identification of Port Scan Toolchains

Port scans are typically at the begin of a chain of events that will lead to the attack and exploitation of a host over a network. Since building an effective defense relies on information what kind of threat an organization is facing, threat intelligence outlining an actor’s modus operandi is a critical ingredient for network security. In this...

A measurement study of DNSSEC misconfigurations

DNSSEC offers protection against spoofing of DNS data by providing origin authentication, ensuring data integrity and authentication of non-existence by using public-key cryptography. Although the relevance of securing a technology as crucial to the Internet as DNS is obvious, the DNSSEC implementation increases the complexity of the deployed...

Content Propagation in Online Social Networks

This thesis presents methods and techniques to analyze content propagation within online social networks (OSNs) using a graph theoretical approach. Important factors and different techniques to analyze and describe content propagation, starting from the smallest entity in a network, representing a user-account, up to complete friendship graphs...

Lognormal infection times of online information spread

The infection times of individuals in online information spread such as the inter-arrival time of Twitter messages or the propagation time of news stories on a social media site can be explained through a convolution of lognormally distributed observation and reaction times of the individual participants. Experimental measurements support the...

Characterizing the Structure of Affiliation Networks

ur society contains all types of organizations, such as companies, research groups and hobby clubs. Affliation networks, as a large and important portion of social networks, consist of individuals and their affiation relations: Two individuals are connected by a link if they belong to the same organization(s). Affliation networks naturally...

A Social Network Model Exhibiting Tunable Overlapping Community Structure

Social networks, as well as many other real-world networks, exhibit overlapping community structure. In this paper, we present formulas which facilitate the computation for characterizing the overlapping community structure of networks. A hypergraph representation of networks with overlapping community structure is introduced. Using the...

How Much do Your Friends Tell About You?: Reconstructing Private Information from the Friendship Graph

After the early land rush and fast exponential growth of online social networking platforms, concerns about how data placed in online social networks may be exploited and abused have begun to appear among mainstream users. Social networking sites have responded to these new public sentiments by introducing privacy filters to their site, allowing...

Lognormal distribution in the digg online social network

We analyse the number of votes, called the digg value, which measures the impact or popularity of submitted information in the Online Social Network Digg. Experiments over five years indicate that the digg value of a story on the first frontpage follows closely a lognormal distribution. While the law of proportionate effect explains lognormal...

Are Friends Overrated?: A Study for the Social Aggregator Digg.com

The key feature of online social networks is the ability of users to become active, make friends and interact with those around them. Such interaction is typically perceived as critical to these platforms; therefore, a significant share of research has investigated the characteristics of social links, friendship relations, community structure,...

Context-Sensitive Sentiment Classification of Short Colloquial Text

The wide-spread popularity of online social networks and the resulting availability of data to researchers has enabled the investigation of new research questions, such as the analysis of information diffusion and how individuals are influencing opinion formation in groups. Many of these new questions however require an automatic assessment of...

Crawling and Detecting Community Structure in Online Social Networks using Local Information

As Online Social Networks (OSNs) become an intensive sub- ject of research for example in computer science, networking, social sci- ences etc., a growing need for valid and useful datasets is present. The time taken to crawl the network is however introducing a bias which should be minimized. Usual ways of addressing this problem are sampling...