1,720,967 research outputs found
On the cyber security issues of the internet infrastructure
Get PDFThe Internet network has received huge attentions by the research community. At a first glance, the network optimization and scalability issues dominate the efforts of researchers and vendors. Many results have been obtained in the last decades: the Internet’s architecture is optimized to be cheap, robust and ubiquitous. In contrast, such a network has never been perfectly secure. During all its evolution, the security threats of the Internet persist as a transversal and endless topic. Nowadays, the Internet network hosts a multitude of mission critical activities. The electronic voting systems and financial services are carried out through it. Governmental institutions, financial and business organizations depend on the performance and the security of the Internet. This role confers to the Internet network a critical characterization. At the same time, the Internet network is a vector of malicious activities, like Denial of Service attacks; many reports of attacks can be found in both academic outcomes and daily news. In order to mitigate this wide range of issues, many research efforts have been carried out in the past decades; unfortunately, the complex architecture and the scale of the Internet make hard the evaluation and the adoption of such proposals. In order to improve the security of the Internet, the research community can benefit from sharing real network data. Unfortunately, privacy and security concerns inhibit the release of these data: its suffices to imagine the big amount of private information (e.g., political preferences or religious belief) it is possible to get while reading the Internet packets exchanged between users and web services. This scenario motivates my research, and represents the context of this dissertation which contributes to the analysis of the security issues of the Internet infrastructures and describes relevant security proposals. In particular, the main outcomes described in this dissertation are:
• the definition of a secure routing protocol for the Internet network able to provide cryptographic guarantees against false route announcement and invalid path attack;
• the definition of a new obfuscation technique that allow the research community to publicly release their real network flows with formal guarantees of security and privacy;
• the evidence of a new kind of leakage of sensitive informations obtained hacking the models used by sundry Machine Learning Algorithms
Replication schemes in Unattended Wireless Sensor Networks
No full textUnattended Wireless Sensor Networks (UWSNs) are networks that operate without on-line data collection entities (Sink Collectors). This configuration enriches their flexibility but, at the same time, introduces new security issues. A challenging issue is data survival: in absence of the sink, in fact, data sensed by network sensors cannot be kept clear from the adversary. Cryptographic schemes, moreover, cannot be easily implemented: cryptographic material as well as sensed data are continuously exposed to the activity of a smart adversary [6]. Several strategies were proposed in literature which collectively attempt to mitigate this challenge. In this paper we investigate the use of replication as a mean to enhance the survival probability of collected data. We propose a scheme that deterministically grants data survival against a focused mobile adversary. We analyze the behavior of our proposal and study its security and efficiency properties to prove its suitability for UWSNs
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Uniqueness of the file systems genome: Supporting arguments and massive experimental measurements
No full textThis paper provides evidence of a distinguished feature of file systems, that we call File System Genome. Such a feature is originated by the locations where the file blocks are placed on the mass-storage device by the operating system during the installation procedure. It appears from our study that the File System Genome is a distinctive feature of each operating system installation. In particular, our extensive set of experiments shows that the installation of the same operating system on two identical hardware configurations generates two different File System Genomes. Further, the application of sound information theory tools, such as min entropy, show that the differences between two File System Genome are considerably relevant. The results provided in this paper constitute the scientific basis for a number of applications in various fields of information technology, such as devices' identification and security
MhRep: Multi-hop replication scheme for data survival in unattended wireless sensor networks
No full textUnattended Wireless Sensors Networks (UWSNs) are emerging Wireless Sensor Networks (WSNs) characterized by periodic absence of trusted entities, like the Sink Collectors. The time periods with no sink attendance, force the network sensors to locally store collected data until the next sink visit. This means that data collection is not performed in real time, but it falls at regular intervals. Such conditions define a different paradigm regarding traditional WSNs and introduce several new security issues, data survival above all. At the best of our knowledge, only two strategies were proposed to mitigate mobile adversary data deletion attack : encryption protocols (implementing backward and/or forward secrecy) and replication. While encryption protocols can impose an extensive computational effort and experience several security issues (like key exposure), replication schemes seem to capture a renewed interest from researchers, since their power requirement seem compatible with the constraints of wireless sensors. In this paper we focus on a new replication scheme and compare its performances with some other proposals, previously presented in literature. The schemes share some model assumptions, in terms of network and adversary attack strategy and objective
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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