Download or read book Algorithmic Aspects of Manipulation and Anonymization in Social Choice and Social Networks written by Talmon, Nimrod and published by Universitätsverlag der TU Berlin. This book was released on 2016-05-20 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a study of several combinatorial problems related to social choice and social networks. The main concern is their computational complexity, with an emphasis on their parameterized complexity. The goal is to devise efficient algorithms for each of the problems studied here, or to prove that, under widely-accepted assumptions, such algorithms cannot exist. The problems discussed in Chapter 3 and in Chapter 4 are about manipulating a given election, where some relationships between the entities of the election are assumed. This can be seen as if the election occurs on top of an underlying social network, connecting the voters participating in the election or the candidates which the voters vote on. The problem discussed in Chapter 3, Combinatorial Candidate Control, is about manipulating an election by changing the set of candidates which the voters vote on. That is, there is an external agent who can add new candidates or delete existing candidates. A combinatorial structure over the candidates is assumed, such that whenever the external agent adds or removes a candidate, a predefined set of candidates (related to the chosen candidate) are added or removed from the election. The problem discussed in Chapter 4, Combinatorial Shift Bribery, is also about manipulating an election. Here, however, the external agent can change the way some voters vote. Specifically, a combinatorial structure over the voters is assumed, such that the external agent can change the position of its preferred candidate in sets of voters, following some predefined patterns. The problem discussed in Chapter 5, Election Anonymization, is also about elections. The main concern here, however, is preserving the privacy of the voters, when the votes are published, along with some additional (private) information. The task is to transform a given election such that each vote would appear at least k times. By doing so, even an adversary which knows how some voters vote, cannot identify individual voters. The problems discussed in Chapter 6 and in Chapter 7 are also about privacy. Specifically, a social network (modeled as a graph) is to become publicly available. The task is to anonymize the graph; that is, to transform the graph such that, for every vertex, there will be at least $k - 1$ other vertices with the same degree. By doing so, even an adversary which knows the degrees of some vertices cannot identify individual vertices. In the problem discussed in Chapter 6, Degree Anonymization by Vertex Addition, the way to achieve anonymity is by introducing new vertices. In the problem discussed in Chapter 7, Degree Anonymization By Graph Contractions, the way to achieve anonymity is by contracting as few edges as possible. The main aim of this thesis, considering the problems mentioned above, is to explore some boundaries between tractability and intractability. Specifically, as most of these problems are computationally intractable (that is, NP-hard or even hard to approximate), some restricted cases and parameterizations for these problems are considered. The goal is to devise efficient algorithms for them, running in polynomial-time when some parameters are assumed to be constant, or, even better, to show that the problems are fixed-parameter tractable for the parameters considered. If such algorithms cannot be devised, then the goal is to prove that these problems are indeed not fixed-parameter tractable with respect to some parameters, or, even better, to show that the problems are NP-hard even when some parameters are assumed to be constant. Diese Dissertation stellt eine Untersuchung von verschiedenen kombinatorischen Problemen im Umfeld von Wahlen und sozialen Netzwerken dar. Das Hauptziel ist die Analyse der Berechnungskomplexität mit dem Schwerpunkt auf der parametrisierten Komplexität. Dabei werden für jedes der untersuchten Probleme effiziente Algorithmen entworfen oder aber gezeigt, dass unter weit akzeptierten Annahmen solche Algorithmen nicht existieren können. Die Probleme, welche im Kapitel 3 und im Kapitel 4 diskutiert werden, modellieren das Manipulieren einer gegebenen Wahl, bei welcher gewisse Beziehungen zwischen den Beteiligten angenommen werden. Dies kann so interpretiert werden, dass die Wahl innerhalb eines Sozialen Netzwerks stattfindet, in dem die Wähler oder die Kandidaten miteinander in Verbindung stehen. Das Problem Combinatorial Candidate Control ONTROL, welches in Kapitel 3 untersucht wird, handelt von der Manipulation einer Wahl durch die änderung der Kandidatenmenge über welche die Wähler abstimmen. Genauer gesagt, gibt es einen externen Agenten, welcher neue Kandidaten hinzufügen oder existierende Kandidaten entfernen kann. Es wird eine kombinatorische Struktur über der Kandidatenmenge angenommen, so dass immer wenn der externe Agent einen Kandidaten hinzufügt oder entfernt, eine vordefinierte Kandidatenmenge (welche mit den ausgewählten Kandidaten in Beziehung steht) ebenfalls hinzugefügt bzw. entfernt wird. Das Problem Combinatorial Shift Bribery, welches in Kapitel 4 untersucht wird, thematisiert ebenfalls die Manipulation einer Wahl. Hier allerdings kann der externe Agent Änderungen des Abstimmungsverhaltens einiger Wähler herbeiführen. Dabei wird eine kombinatorische Struktur über den Wählern angenommen, so dass der externe Agent die Position des von ihm präferierten Kandidaten bei mehreren Wählern entsprechend vordefinierter Muster gleichzeitig ändern kann. Das Problem Election Anonymization, welches in Kapitel 5 untersucht wird, befasst sich ebenso mit Wahlen. Das Hauptanliegen hier ist es jedoch, die Privatsphäre der Wähler bei der Veröffentlichung der Stimmenabgaben zusammen mit einigen zusätzlichen (privaten) Informationen aufrecht zu erhalten. Die Aufgabe ist es eine gegebene Wahl so zu verändern, dass jede Stimmenabgabe mindestens k-fach vorkommt. Dadurch kann noch nicht einmal ein Gegenspieler einzelne Wähler identifizieren, wenn er die Stimmenabgaben einiger Wähler bereits kennt. Die in Kapitel 6 und 7 untersuchten Probleme behandeln gleichermaßen Privatsphärenaspekte. Präziser gesagt, geht es darum, dass ein soziales Netzwerk (modelliert als Graph) veröffentlicht werden soll. Die Aufgabe ist es den Graphen zu anonymisieren; dies bedeutet man verändert den Graphen, so dass es für jeden Knoten mindestens k − 1 weitere Knoten mit dem selben Grad gibt. Dadurch wird erreicht, dass selbst ein Gegenspieler, welcher die Knotengrade einiger Knoten kennt, nicht in der Lage ist einzelne Knoten zu identifizieren. Bei dem Problem Degree Anonymization by Vertex Addition, welches in Kapitel 6 untersucht wird, wird Anonymität durch Einführung neuer Knoten erreicht. Bei dem Problem Degree Anonymization by Graph Contractions, welches in Kapitel 7 untersucht wird, wird Anonymität durch die Kontraktion von möglichst wenigen Kanten erreicht. Das Hauptanliegen dieser Dissertation in Bezug auf die obig genannten Probleme ist es die Grenzen der effizienten Lösbarkeit auszuloten. Insbesondere da die meisten dieser Probleme berechnungsschwer (genauer NP-schwer bzw. sogar schwer zu approximieren) sind, werden einige eingeschränkte Fälle und Parametrisierungen der Probleme betrachtet. Das Ziel ist es effiziente Algorithmen für sie zu entwickeln, welche in Polynomzeit laufen, wenn einige Parameter konstante Werte aufweisen, oder besser noch zu zeigen, dass die Probleme “fixed-parameter tractable” für die betrachteten Parameter sind. Wenn solche Algorithmen nicht gefunden werden können, dann ist es das Ziel zu beweisen, dass diese Probleme tatsächlich nicht “fixed-parameter tractable” bezüglich der entsprechenden Parameter sind, oder noch besser zu zeigen, dass die Probleme NP-schwer sind, sogar wenn die entsprechenden Parameter konstante Werte aufweisen.

Download or read book Security Privacy and Anonymization in Social Networks Emerging Research and Opportunities written by Tripathy, B. K. and published by IGI Global. This book was released on 2018-01-19 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technology has become profoundly integrated into modern society; however, this increases the risk of vulnerabilities, such as hacking and other system errors, along with other online threats. Security, Privacy, and Anonymization in Social Networks: Emerging Research and Opportunities is a pivotal reference source for the most up-to-date research on edge clustering models and weighted social networks. Presenting widespread coverage across a range of applicable perspectives and topics, such as neighborhood attacks, fast k-degree anonymization (FKDA), and vertex-clustering algorithms, this book is ideally designed for academics, researchers, post-graduates, and practitioners seeking current research on undirected networks and greedy algorithms for social network anonymization.

Download or read book Automata Languages and Programming written by Fedor V. Fomin and published by Springer. This book was released on 2013-07-03 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume set of LNCS 7965 and LNCS 7966 constitutes the refereed proceedings of the 40th International Colloquium on Automata, Languages and Programming, ICALP 2013, held in Riga, Latvia, in July 2013. The total of 124 revised full papers presented were carefully reviewed and selected from 422 submissions. They are organized in three tracks focussing on algorithms, complexity and games; logic, semantics, automata and theory of programming; and foundations of networked computation.

Download or read book Degree constrained editing of small degree graphs written by Nichterlein, Andre and published by Universitätsverlag der TU Berlin. This book was released on 2015-07-03 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis deals with degree-constrained graph modification problems. In particular, we investigate the computational complexity of DAG Realization and Degree Anonymity. The DAG Realization problem is, given a multiset of positive integer pairs, to decide whether there is a realizing directed acyclic graph (DAG), that is, pairs are one-to-one assigned to vertices such that the indegree and the outdegree of every vertex coincides with the two integers of the assigned pair. The Degree Anonymity problem is, given an undirected graph G and two positive integers k and s, to decide whether at most s graph modification operations can be performed in G in order to obtain a k-anonymous graph, that is, a graph where for each vertex there are k − 1 other vertices with the same degree. We classify both problems as NP-complete, that is, there are presumably no polynomial-time algorithms that can solve every instance of these problems. Confronted with this worst-case intractability, we perform a parameterized complexity study in order to detect efficiently solvable special cases that are still practically relevant. The goal herein is to develop fixed-parameter algorithms where the seemingly unavoidable exponential dependency in the running time is confined to a parameter of the input. If the parameter is small, then the corresponding fixed-parameter algorithm is fast. The parameter thus measures some structure in the input whose exploitation makes the particular input tractable. Considering Degree Anonymity, two natural parameters provided with the input are anonymity level k and solution size s. However, we will show that Degree Anonymity is W[1]-hard with respect to the parameter s even if k = 2. This means that the existence of fixed-parameter algorithms for s and k is very unlikely. Thus, other parameters have to be considered. We will show that the parameter maximum vertex degree is very promising for both DAG Realization and Degree Anonymity. Herein, for Degree Anonymity, we consider the maximum degree of the input graph. Considering DAG Realization, we take the maximum degree in a realizing DAG. Due to the problem definition, we can easily determine the maximum degree by taking the maximum over all integers in the given multiset. We provide fixed-parameter algorithms with respect to the maximum degree for DAG Realization and for Anonym E-Ins. The later is the variant of Degree Anonymity when only edge insertions are allowed as modification operations. If we allow edge deletions or vertex deletions as graph modification operations, then we can show that the corresponding variants of Degree Anonymity—called Anonym V-Del and Anonym E-Del—are NP-complete even if the maximum vertex degree is seven. Moreover, we provide strong intractability results for Anonym E-Del and Anonym V-Del proving that they remain NP-complete in several restricted graph classes. Studying the approximability of natural optimization problems associated with Anonym E-Del or Anonym V-Del, we obtain negative results showing that none of the considered problems can be approximated in polynomial time better than within a factor of n^(1/2) where n denotes the number of vertices in the input. Furthermore, for the optimization variants where the solution size s is given and the task is to maximize the anonymity level k, this inapproximability even holds if we allow a running time that is exponential in s. Observe that DAG Realization also can be seen as degree-constrained graph modification problem where only arc insertions are allowed: Starting with an arcless graph, the task is to insert arcs to obtain a realizing DAG for the given multiset. The above classification with respect to the parameter maximum degree shows that in graphs with small maximum degree the modification operation edge respectively arc insertion is easier than vertex or edge deletion. There is a plausible explanation for this behavior: When the maximum degree is small, then there is a high freedom in inserting edges or arcs as for a given vertex almost all other vertices can be chosen as new neighbor. Observe that for DAG Realization the additional requirement that the directed graph shall be acyclic restricts this freedom. In Anonym E-Ins, we do not have restrictions on this freedom. In fact, exploiting this freedom in our implementation for Anonym E-Ins, we show that our theoretical ideas can be turned into successful heuristics and lower bounds. Experiments on several large-scale real-world datasets show that our implementation significantly improves on a recent heuristic and provides (provably) optimal solutions on about 21 % (56 of 260) of the real-world data.

Download or read book Advanced Research in Data Privacy written by Guillermo Navarro-Arribas and published by Springer. This book was released on 2014-08-21 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of the research work on data privacy and privacy enhancing technologies carried by the participants of the ARES project. ARES (Advanced Research in Privacy an Security, CSD2007-00004) has been one of the most important research projects funded by the Spanish Government in the fields of computer security and privacy. It is part of the now extinct CONSOLIDER INGENIO 2010 program, a highly competitive program which aimed to advance knowledge and open new research lines among top Spanish research groups. The project started in 2007 and will finish this 2014. Composed by 6 research groups from 6 different institutions, it has gathered an important number of researchers during its lifetime. Among the work produced by the ARES project, one specific work package has been related to privacy. This books gathers works produced by members of the project related to data privacy and privacy enhancing technologies. The presented works not only summarize important research carried in the project but also serve as an overview of the state of the art in current research on data privacy and privacy enhancing technologies.

Download or read book Computing and Combinatorics written by Yixin Cao and published by Springer. This book was released on 2017-07-25 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 23rd International Conference on Computing and Combinatorics, COCOON 2017, held in Hiong Kong, China, in August 2017. The 56 full papers papers presented in this book were carefully reviewed and selected from 119 submissions. The papers cover various topics, including algorithms and data structures, complexity theory and computability, algorithmic game theory, computational learning theory, cryptography, computationalbiology, computational geometry and number theory, graph theory, and parallel and distributed computing.

Download or read book Computational Social Networks written by Ajith Abraham and published by Springer Science & Business Media. This book was released on 2012-08-14 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the second of three volumes that illustrate the concept of social networks from a computational point of view. The book contains contributions from a international selection of world-class experts, concentrating on topics relating to security and privacy (the other two volumes review Tools, Perspectives, and Applications, and Mining and Visualization in CSNs). Topics and features: presents the latest advances in security and privacy issues in CSNs, and illustrates how both organizations and individuals can be protected from real-world threats; discusses the design and use of a wide range of computational tools and software for social network analysis; describes simulations of social networks, and the representation and analysis of social networks, with a focus on issues of security, privacy, and anonymization; provides experience reports, survey articles, and intelligence techniques and theories relating to specific problems in network technology.

Download or read book Social Network Analytics for Contemporary Business Organizations written by Bansal, Himani and published by IGI Global. This book was released on 2018-03-23 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: Social technology is quickly becoming a vital tool in our personal, educational, and professional lives. Its use must be further examined in order to determine the role of social media technology in organizational settings to promote business development and growth. Social Network Analytics for Contemporary Business Organizations is a critical scholarly resource that analyzes the application of social media in business applications. Featuring coverage on a broad range of topics, such as business management, dynamic networks, and online interaction, this book is geared towards professionals, researchers, academics, students, managers, and practitioners actively involved in the business industry.

Download or read book Experimental Algorithms written by Joachim Gudmundsson and published by Springer. This book was released on 2014-06-09 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 13th International Symposium on Experimental Algorithms, SEA 2014, held in Copenhagen, Denmark, in June/July 2014. The 36 revised full papers presented together with 3 invited presentations were carefully reviewed and selected from 81 submissions. The papers are organized in topical sections on combinatorial optimization, data structures, graph drawing, shortest path, strings, graph algorithms and suffix structures.

Download or read book Privacy in Social Networks written by Elena Zheleva and published by Morgan & Claypool Publishers. This book was released on 2013-03-01 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis lecture provides a survey of work on privacy in online social networks (OSNs). This work encompasses concerns of users as well as service providers and third parties. Our goal is to approach such concerns from a computer-science perspective, and building upon existing work on privacy, security, statistical modeling and databases to provide an overview of the technical and algorithmic issues related to privacy in OSNs. We start our survey by introducing a simple OSN data model and describe common statistical-inference techniques that can be used to infer potentially sensitive information. Next, we describe some privacy definitions and privacy mechanisms for data publishing. Finally, we describe a set of recent techniques for modeling, evaluating, and managing individual users' privacy risk within the context of OSNs. Table of Contents: Introduction / A Model for Online Social Networks / Types of Privacy Disclosure / Statistical Methods for Inferring Information in Networks / Anonymity and Differential Privacy / Attacks and Privacy-preserving Mechanisms / Models of Information Sharing / Users' Privacy Risk / Management of Privacy Settings

Download or read book Research Anthology on Strategies for Using Social Media as a Service and Tool in Business written by Management Association, Information Resources and published by IGI Global. This book was released on 2021-05-28 with total page 1865 pages. Available in PDF, EPUB and Kindle. Book excerpt: Social media has become an integral part of society as social networking has become a main form of communication and human interaction. To stay relevant, businesses have adopted social media tactics to interact with consumers, conduct business, and remain competitive. Social technologies have reached a vital point in the business world, being essential in strategic decision-making processes, building relationships with consumers, marketing and branding efforts, and other important areas. While social media continues to gain importance in modern society, it is essential to determine how it functions in contemporary business. The Research Anthology on Strategies for Using Social Media as a Service and Tool in Business provides updated information on how businesses are strategically using social media and explores the role of social media in keeping businesses competitive in the global economy. The chapters will discuss how social tools work, what services businesses are utilizing, both the benefits and challenges to how social media is changing the modern business atmosphere, and more. This book is essential for researchers, instructors, social media managers, business managers, students, executives, practitioners, industry professionals, social media analysts, and all audiences interested in how social media is being used in modern businesses as both a service and integral tool.

Download or read book Big Data and Social Media Analytics written by Mehmet Çakırtaş and published by Springer Nature. This book was released on 2021-07-05 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited book provides techniques which address various aspects of big data collection and analysis from social media platforms and beyond. It covers efficient compression of large networks, link prediction in hashtag graphs, visual exploration of social media data, identifying motifs in multivariate data, social media surveillance to enhance search and rescue missions, recommenders for collaborative filtering and safe travel plans to high risk destinations, analysis of cyber influence campaigns on YouTube, impact of location on business rating, bibliographical and co-authorship network analysis, and blog data analytics. All these trending topics form a major part of the state of the art in social media and big data analytics. Thus, this edited book may be considered as a valuable source for readers interested in grasping some of the most recent advancements in this high trending domain.

Download or read book Link Mining Models Algorithms and Applications written by Philip S. Yu and published by Springer Science & Business Media. This book was released on 2010-09-16 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers detailed surveys and systematic discussion of models, algorithms and applications for link mining, focusing on theory and technique, and related applications: text mining, social network analysis, collaborative filtering and bioinformatics.

Download or read book The SAGE Encyclopedia of the Internet written by Barney Warf and published by SAGE. This book was released on 2018-05-16 with total page 2343 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Internet needs no introduction, and its significance today can hardly be exaggerated. Today, more people are more connected technologically to one another than at any other time in human existence. For a large share of the world’s people, the Internet, text messaging, and various other forms of digital social media such as Facebook have become thoroughly woven into the routines and rhythms of daily life. The Internet has transformed how we seek information, communicate, entertain ourselves, find partners, and, increasingly, it shapes our notions of identity and community. The SAGE Encyclopedia of the Internet addresses the many related topics pertaining to cyberspace, email, the World Wide Web, and social media. Entries will range from popular topics such as Alibaba and YouTube to important current controversies such as Net neutrality and cyberterrorism. The goal of the encyclopedia is to provide the most comprehensive collection of authoritative entries on the Internet available, written in a style accessible to academic and non-academic audiences alike.

Download or read book Guide to Data Privacy written by Vicenç Torra and published by Springer Nature. This book was released on 2022-11-04 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data privacy technologies are essential for implementing information systems with privacy by design. Privacy technologies clearly are needed for ensuring that data does not lead to disclosure, but also that statistics or even data-driven machine learning models do not lead to disclosure. For example, can a deep-learning model be attacked to discover that sensitive data has been used for its training? This accessible textbook presents privacy models, computational definitions of privacy, and methods to implement them. Additionally, the book explains and gives plentiful examples of how to implement—among other models—differential privacy, k-anonymity, and secure multiparty computation. Topics and features: Provides integrated presentation of data privacy (including tools from statistical disclosure control, privacy-preserving data mining, and privacy for communications) Discusses privacy requirements and tools for different types of scenarios, including privacy for data, for computations, and for users Offers characterization of privacy models, comparing their differences, advantages, and disadvantages Describes some of the most relevant algorithms to implement privacy models Includes examples of data protection mechanisms This unique textbook/guide contains numerous examples and succinctly and comprehensively gathers the relevant information. As such, it will be eminently suitable for undergraduate and graduate students interested in data privacy, as well as professionals wanting a concise overview. Vicenç Torra is Professor with the Department of Computing Science at Umeå University, Umeå, Sweden.

Download or read book Data Mining written by Robert Stahlbock and published by Springer Science & Business Media. This book was released on 2009-11-10 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the course of the last twenty years, research in data mining has seen a substantial increase in interest, attracting original contributions from various disciplines including computer science, statistics, operations research, and information systems. Data mining supports a wide range of applications, from medical decision making, bioinformatics, web-usage mining, and text and image recognition to prominent business applications in corporate planning, direct marketing, and credit scoring. Research in information systems equally reflects this inter- and multidisciplinary approach, thereby advocating a series of papers at the intersection of data mining and information systems research. This special issue of Annals of Information Systems contains original papers and substantial extensions of selected papers from the 2007 and 2008 International Conference on Data Mining (DMIN’07 and DMIN’08, Las Vegas, NV) that have been rigorously peer-reviewed. The issue brings together topics on both information systems and data mining, and aims to give the reader a current snapshot of the contemporary research and state of the art practice in data mining.

Download or read book Recommendation and Search in Social Networks written by Özgür Ulusoy and published by Springer. This book was released on 2015-02-12 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited volume offers a clear in-depth overview of research covering a variety of issues in social search and recommendation systems. Within the broader context of social network analysis it focuses on important and up-coming topics such as real-time event data collection, frequent-sharing pattern mining, improvement of computer-mediated communication, social tagging information, search system personalization, new detection mechanisms for the identification of online user groups, and many more. The twelve contributed chapters are extended versions of conference papers as well as completely new invited chapters in the field of social search and recommendation systems. This first-of-its kind survey of current methods will be of interest to researchers from both academia and industry working in the field of social networks.