491 research outputs found
Deep learning for situational understanding
Situational understanding (SU) requires a combination
of insight â the ability to accurately perceive an existing
situation â and foresight â the ability to anticipate how
an existing situation may develop in the future. SU involves
information fusion as well as model representation and inference.
Commonly, heterogenous data sources must be exploited in the
fusion process: often including both hard and soft data products.
In a coalition context, data and processing resources will also be
distributed and subjected to restrictions on information sharing.
It will often be necessary for a human to be in the loop in SU
processes, to provide key input and guidance, and to interpret
outputs in a way that necessitates a degree of transparency
in the processing: systems cannot be âblack boxesâ. In this
paper, we characterize the Coalition Situational Understanding
(CSU) problem in terms of fusion, temporal, distributed, and
human requirements. There is currently significant interest in
deep learning (DL) approaches for processing both hard and
soft data. We analyze the state-of-the-art in DL in relation to
these requirements for CSU, and identify areas where there is
currently considerable promise, and key gaps
Intrusion Detection from Heterogenous Sensors
RĂSUMĂ
De nos jours, la protection des systĂšmes et rĂ©seaux informatiques contre diffĂ©rentes attaques avancĂ©es et distribuĂ©es constitue un dĂ©fi vital pour leurs propriĂ©taires. Lâune des menaces critiques Ă la sĂ©curitĂ© de ces infrastructures informatiques sont les attaques rĂ©alisĂ©es par des individus dont les intentions sont malveillantes, quâils soient situĂ©s Ă lâintĂ©rieur et Ă lâextĂ©rieur de lâenvironnement du systĂšme, afin dâabuser des services disponibles, ou de rĂ©vĂ©ler des informations confidentielles. Par consĂ©quent, la gestion et la surveillance des systĂšmes informatiques est un dĂ©fi considĂ©rable considĂ©rant que de nouvelles menaces et attaques sont dĂ©couvertes sur une base quotidienne.
Les systĂšmes de dĂ©tection dâintrusion, Intrusion Detection Systems (IDS) en anglais, jouent un rĂŽle clĂ© dans la surveillance et le contrĂŽle des infrastructures de rĂ©seau informatique. Ces systĂšmes inspectent les Ă©vĂ©nements qui se produisent dans les systĂšmes et rĂ©seaux informatiques et en cas de dĂ©tection dâactivitĂ© malveillante, ces derniers gĂ©nĂšrent des alertes afin de fournir les dĂ©tails des attaques survenues. Cependant, ces systĂšmes prĂ©sentent certaines limitations qui mĂ©ritent dâĂȘtre adressĂ©es si nous souhaitons les rendre suffisamment fiables pour rĂ©pondre aux besoins rĂ©els. Lâun des principaux dĂ©fis qui caractĂ©rise les IDS est le grand nombre dâalertes redondantes et non pertinentes ainsi que le taux de faux-positif gĂ©nĂ©rĂ©s, faisant de leur analyse une tĂąche difficile pour les administrateurs de sĂ©curitĂ© qui tentent de dĂ©terminer et dâidentifier les alertes qui sont rĂ©ellement importantes. Une partie du problĂšme rĂ©side dans le fait que la plupart des IDS ne prennent pas compte les informations contextuelles (type de systĂšmes, applications, utilisateurs, rĂ©seaux, etc.) reliĂ©es Ă lâattaque. Ainsi, une grande partie des alertes gĂ©nĂ©rĂ©es par les IDS sont non pertinentes en ce sens quâelles ne permettent de comprendre lâattaque dans son contexte et ce, malgrĂ© le fait que le systĂšme ait rĂ©ussi Ă correctement dĂ©tecter une intrusion. De plus, plusieurs IDS limitent leur dĂ©tection Ă un seul type de capteur, ce qui les rend inefficaces pour dĂ©tecter de nouvelles attaques complexes. Or, ceci est particuliĂšrement important dans le cas des attaques ciblĂ©es qui tentent dâĂ©viter la dĂ©tection par IDS conventionnels et par dâautres produits de sĂ©curitĂ©. Bien que de nombreux administrateurs systĂšme incorporent avec succĂšs des informations de contexte ainsi que diffĂ©rents types de capteurs et journaux dans leurs analyses, un problĂšme important avec cette approche reste le manque dâautomatisation, tant au niveau du stockage que de lâanalyse.
Afin de rĂ©soudre ces problĂšmes dâapplicabilitĂ©, divers types dâIDS ont Ă©tĂ© proposĂ©s dans les derniĂšres annĂ©es, dont les IDS de type composant pris sur Ă©tagĂšre, commercial off-the-shelf (COTS) en anglais, qui sont maintenant largement utilisĂ©s dans les centres dâopĂ©rations de sĂ©curitĂ©, Security Operations Center (SOC) en anglais, de plusieurs grandes organisations. Dâun point de vue plus gĂ©nĂ©ral, les diffĂ©rentes approches proposĂ©es peuvent ĂȘtre classĂ©es en diffĂ©rentes catĂ©gories : les mĂ©thodes basĂ©es sur lâapprentissage machine, tel que les rĂ©seaux bayĂ©siens, les mĂ©thodes dâextraction de donnĂ©es, les arbres de dĂ©cision, les rĂ©seaux de neurones, etc., les mĂ©thodes impliquant la corrĂ©lation dâalertes et les approches fondĂ©es sur la fusion dâalertes, les systĂšmes de dĂ©tection dâintrusion sensibles au contexte, les IDS dit distribuĂ©s et les IDS qui reposent sur la notion dâontologie de base. Ătant donnĂ© que ces diffĂ©rentes approches se concentrent uniquement sur un ou quelques-uns des dĂ©fis courants reliĂ©s aux IDS, au meilleure de notre connaissance, le problĂšme dans son ensemble nâa pas Ă©tĂ© rĂ©solu. Par consĂ©quent, il nâexiste aucune approche permettant de couvrir tous les dĂ©fis des IDS modernes prĂ©cĂ©demment mentionnĂ©s. Par exemple, les systĂšmes qui reposent sur des mĂ©thodes dâapprentissage machine classent les Ă©vĂ©nements sur la base de certaines caractĂ©ristiques en fonction du comportement observĂ© pour un type dâĂ©vĂ©nements, mais ils ne prennent pas en compte les informations reliĂ©es au contexte et les relations pouvant exister entre plusieurs Ă©vĂ©nements. La plupart des techniques de corrĂ©lation dâalerte proposĂ©es ne considĂšrent que la corrĂ©lation entre plusieurs capteurs du mĂȘme type ayant un Ă©vĂ©nement commun et une sĂ©mantique dâalerte similaire (corrĂ©lation homogĂšne), laissant aux administrateurs de sĂ©curitĂ© la tĂąche dâeffectuer la corrĂ©lation entre les diffĂ©rents types de capteurs hĂ©tĂ©rogĂšnes. Pour leur part, les approches sensibles au contexte nâemploient que des aspects limitĂ©s du contexte sous-jacent. Une autre limitation majeure des diffĂ©rentes approches proposĂ©es est lâabsence dâĂ©valuation prĂ©cise basĂ©e sur des ensembles de donnĂ©es qui contiennent des scĂ©narios dâattaque complexes et modernes.
Ă cet effet, lâobjectif de cette thĂšse est de concevoir un systĂšme de corrĂ©lation dâĂ©vĂ©nements qui peut prendre en considĂ©ration plusieurs types hĂ©tĂ©rogĂšnes de capteurs ainsi que les journaux de plusieurs applications (par exemple, IDS/IPS, pare-feu, base de donnĂ©es, systĂšme dâexploitation, antivirus, proxy web, routeurs, etc.). Cette mĂ©thode permettra de dĂ©tecter des attaques complexes qui laissent des traces dans les diffĂ©rents systĂšmes, et dâincorporer les informations de contexte dans lâanalyse afin de rĂ©duire les faux-positifs. Nos contributions peuvent ĂȘtre divisĂ©es en quatre parties principales : 1) Nous proposons la Pasargadae, une solution complĂšte sensible au contexte et reposant sur une ontologie de corrĂ©lation des Ă©vĂ©nements, laquelle effectue automatiquement la corrĂ©lation des Ă©vĂ©nements par lâanalyse des informations recueillies auprĂšs de diverses sources. Pasargadae utilise le concept dâontologie pour reprĂ©senter et stocker des informations sur les Ă©vĂ©nements, le contexte et les vulnĂ©rabilitĂ©s, les scĂ©narios dâattaques, et utilise des rĂšgles dâontologie de logique simple Ă©crites en Semantic Query-Enhance Web Rule Language (SQWRL) afin de corrĂ©ler diverse informations et de filtrer les alertes non pertinentes, en double, et les faux-positifs. 2) Nous proposons une approche basĂ©e sur, mĂ©ta-Ă©vĂ©nement , tri topologique et lâapproche corrĂ©lation dâĂ©vĂ©nement basĂ©e sur sĂ©mantique qui emploie Pasargadae pour effectuer la corrĂ©lation dâĂ©vĂ©nements Ă travers les Ă©vĂ©nements collectĂ©s de plusieurs capteurs rĂ©partis dans un rĂ©seau informatique. 3) Nous proposons une approche alerte de fusion basĂ©e sur sĂ©mantique, contexte sensible, qui sâappuie sur certains des sous-composantes de Pasargadae pour effectuer une alerte fusion hĂ©tĂ©rogĂšne recueillies auprĂšs IDS hĂ©tĂ©rogĂšnes. 4) Dans le but de montrer le niveau de flexibilitĂ© de Pasargadae, nous lâutilisons pour mettre en oeuvre dâautres approches proposĂ©es dâalertes et de corrĂ©lation dâĂ©vĂ©nements. La somme de ces contributions reprĂ©sente une amĂ©lioration significative de lâapplicabilitĂ© et la fiabilitĂ© des IDS dans des situations du monde rĂ©el.
Afin de tester la performance et la flexibilitĂ© de lâapproche de corrĂ©lation dâĂ©vĂ©nements proposĂ©s, nous devons aborder le manque dâinfrastructures expĂ©rimental adĂ©quat pour la sĂ©curitĂ© du rĂ©seau. Une Ă©tude de littĂ©rature montre que les approches expĂ©rimentales actuelles ne sont pas adaptĂ©es pour gĂ©nĂ©rer des donnĂ©es de rĂ©seau de grande fidĂ©litĂ©. Par consĂ©quent, afin dâaccomplir une Ă©valuation complĂšte, dâabord, nous menons nos expĂ©riences sur deux scĂ©narios dâĂ©tude dâanalyse de cas distincts, inspirĂ©s des ensembles de donnĂ©es dâĂ©valuation DARPA 2000 et UNB ISCX IDS. Ensuite, comme une Ă©tude dĂ©posĂ©e complĂšte, nous employons Pasargadae dans un vrai rĂ©seau informatique pour une pĂ©riode de deux semaines pour inspecter ses capacitĂ©s de dĂ©tection sur un vrai terrain trafic de rĂ©seau. Les rĂ©sultats obtenus montrent que, par rapport Ă dâautres amĂ©liorations IDS existants, les contributions proposĂ©es amĂ©liorent considĂ©rablement les performances IDS (taux de dĂ©tection) tout en rĂ©duisant les faux positifs, non pertinents et alertes en double.----------ABSTRACT
Nowadays, protecting computer systems and networks against various distributed and multi-steps attack has been a vital challenge for their owners. One of the essential threats to the security of such computer infrastructures is attacks by malicious individuals from inside and outside of the system environment to abuse available services, or reveal their confidential information. Consequently, managing and supervising computer systems is a considerable challenge, as new threats and attacks are discovered on a daily basis.
Intrusion Detection Systems (IDSs) play a key role in the surveillance and monitoring of computer network infrastructures. These systems inspect events occurred in computer systems and networks and in case of any malicious behavior they generate appropriate alerts describing the attacksâ details. However, there are a number of shortcomings that need to be addressed to make them reliable enough in the real-world situations. One of the fundamental challenges in real-world IDS is the large number of redundant, non-relevant, and false positive alerts that they generate, making it a difficult task for security administrators to determine and identify real and important alerts. Part of the problem is that most of the IDS do not take into account contextual information (type of systems, applications, users, networks, etc.), and therefore a large portion of the alerts are non-relevant in that even though they correctly recognize an intrusion, the intrusion fails to reach its objectives. Additionally, to detect newer and complicated attacks, relying on only one detection sensor type is not adequate, and as a result many of the current IDS are unable to detect them. This is especially important with respect to targeted attacks that try to avoid detection by conventional IDS and by other security products. While many system administrators are known to successfully incorporate context information and many different types of sensors and logs into their analysis, an important problem with this approach is the lack of automation in both storage and analysis. In order to address these problems in IDS applicability, various IDS types have been proposed in the recent years and commercial off-the-shelf (COTS) IDS products have found their way into Security Operations Centers (SOC) of many large organizations. From a general perspective, these works can be categorized into: machine learning based approaches including Bayesian networks, data mining methods, decision trees, neural networks, etc., alert correlation and alert fusion based approaches, context-aware intrusion detection systems, distributed intrusion detection systems, and ontology based intrusion detection systems. To the best of our knowledge, since these works only focus on one or few of the IDS challenges, the problem as a whole has not been resolved. Hence, there is no comprehensive work addressing all the mentioned challenges of modern intrusion detection systems. For example, works that utilize machine learning approaches only classify events based on some features depending on behavior observed with one type of events, and they do not take into account contextual information and event interrelationships. Most of the proposed alert correlation techniques consider correlation only across multiple sensors of the same type having a common event and alert semantics (homogeneous correlation), leaving it to security administrators to perform correlation across heterogeneous types of sensors. Context-aware approaches only employ limited aspects of the underlying context. The lack of accurate evaluation based on the data sets that encompass modern complex attack scenarios is another major shortcoming of most of the proposed approaches.
The goal of this thesis is to design an event correlation system that can correlate across several heterogeneous types of sensors and logs (e.g. IDS/IPS, firewall, database, operating system, anti-virus, web proxy, routers, etc.) in order to hope to detect complex attacks that leave traces in various systems, and incorporate context information into the analysis, in order to reduce false positives. To this end, our contributions can be split into 4 main parts: 1) we propose the Pasargadae comprehensive context-aware and ontology-based event correlation framework that automatically performs event correlation by reasoning on the information collected from various information resources. Pasargadae uses ontologies to represent and store information on events, context and vulnerability information, and attack scenarios, and uses simple ontology logic rules written in Semantic Query-Enhance Web Rule Language (SQWRL) to correlate various information and filter out non-relevant alerts and duplicate alerts, and false positives. 2) We propose a meta-event based, topological sort based and semantic-based event correlation approach that employs Pasargadae to perform event correlation across events collected form several sensors distributed in a computer network. 3) We propose a semantic-based context-aware alert fusion approach that relies on some of the subcomponents of Pasargadae to perform heterogeneous alert fusion collected from heterogeneous IDS. 4) In order to show the level of flexibility of Pasargadae, we use it to implement some other proposed alert and event correlation approaches. The sum of these contributions represent a significant improvement in the applicability and reliability of IDS in real-world situations.
In order to test the performance and flexibility of the proposed event correlation approach, we need to address the lack of experimental infrastructure suitable for network security. A study of the literature shows that current experimental approaches are not appropriate to generate high fidelity network data. Consequently, in order to accomplish a comprehensive evaluation, first, we conduct our experiments on two separate analysis case study scenarios, inspired from the DARPA 2000 and UNB ISCX IDS evaluation data sets. Next, as a complete field study, we employ Pasargadae in a real computer network for a two weeks period to inspect its detection capabilities on a ground truth network traffic. The results obtained show that compared to other existing IDS improvements, the proposed contributions significantly improve IDS performance (detection rate) while reducing false positives, non-relevant and duplicate alerts
Data-driven Computational Social Science: A Survey
Social science concerns issues on individuals, relationships, and the whole
society. The complexity of research topics in social science makes it the
amalgamation of multiple disciplines, such as economics, political science, and
sociology, etc. For centuries, scientists have conducted many studies to
understand the mechanisms of the society. However, due to the limitations of
traditional research methods, there exist many critical social issues to be
explored. To solve those issues, computational social science emerges due to
the rapid advancements of computation technologies and the profound studies on
social science. With the aids of the advanced research techniques, various
kinds of data from diverse areas can be acquired nowadays, and they can help us
look into social problems with a new eye. As a result, utilizing various data
to reveal issues derived from computational social science area has attracted
more and more attentions. In this paper, to the best of our knowledge, we
present a survey on data-driven computational social science for the first time
which primarily focuses on reviewing application domains involving human
dynamics. The state-of-the-art research on human dynamics is reviewed from
three aspects: individuals, relationships, and collectives. Specifically, the
research methodologies used to address research challenges in aforementioned
application domains are summarized. In addition, some important open challenges
with respect to both emerging research topics and research methods are
discussed.Comment: 28 pages, 8 figure
Lidar-based Obstacle Detection and Recognition for Autonomous Agricultural Vehicles
Today, agricultural vehicles are available that can drive autonomously and follow exact route plans more precisely than human operators. Combined with advancements in precision agriculture, autonomous agricultural robots can reduce manual labor, improve workflow, and optimize yield. However, as of today, human operators are still required for monitoring the environment and acting upon potential obstacles in front of the vehicle. To eliminate this need, safety must be ensured by accurate and reliable obstacle detection and avoidance systems.In this thesis, lidar-based obstacle detection and recognition in agricultural environments has been investigated. A rotating multi-beam lidar generating 3D point clouds was used for point-wise classification of agricultural scenes, while multi-modal fusion with cameras and radar was used to increase performance and robustness. Two research perception platforms were presented and used for data acquisition. The proposed methods were all evaluated on recorded datasets that represented a wide range of realistic agricultural environments and included both static and dynamic obstacles.For 3D point cloud classification, two methods were proposed for handling density variations during feature extraction. One method outperformed a frequently used generic 3D feature descriptor, whereas the other method showed promising preliminary results using deep learning on 2D range images. For multi-modal fusion, four methods were proposed for combining lidar with color camera, thermal camera, and radar. Gradual improvements in classification accuracy were seen, as spatial, temporal, and multi-modal relationships were introduced in the models. Finally, occupancy grid mapping was used to fuse and map detections globally, and runtime obstacle detection was applied on mapped detections along the vehicle path, thus simulating an actual traversal.The proposed methods serve as a first step towards full autonomy for agricultural vehicles. The study has thus shown that recent advancements in autonomous driving can be transferred to the agricultural domain, when accurate distinctions are made between obstacles and processable vegetation. Future research in the domain has further been facilitated with the release of the multi-modal obstacle dataset, FieldSAFE
Big Data for Traffic Estimation and Prediction: A Survey of Data and Tools
Big data has been used widely in many areas including the transportation
industry. Using various data sources, traffic states can be well estimated and
further predicted for improving the overall operation efficiency. Combined with
this trend, this study presents an up-to-date survey of open data and big data
tools used for traffic estimation and prediction. Different data types are
categorized and the off-the-shelf tools are introduced. To further promote the
use of big data for traffic estimation and prediction tasks, challenges and
future directions are given for future studies
Geospatial Information Research: State of the Art, Case Studies and Future Perspectives
Geospatial information science (GI science) is concerned with the development and application of geodetic and information science methods for modeling, acquiring, sharing, managing, exploring, analyzing, synthesizing, visualizing, and evaluating data on spatio-temporal phenomena related to the Earth. As an interdisciplinary scientific discipline, it focuses on developing and adapting information technologies to understand processes on the Earth and human-place interactions, to detect and predict trends and patterns in the observed data, and to support decision making. The authors â members of DGK, the Geoinformatics division, as part of the Committee on Geodesy of the Bavarian Academy of Sciences and Humanities, representing geodetic research and university teaching in Germany â have prepared this paper as a means to point out future research questions and directions in geospatial information science. For the different facets of geospatial information science, the state of art is presented and underlined with mostly own case studies. The paper thus illustrates which contributions the German GI community makes and which research perspectives arise in geospatial information science. The paper further demonstrates that GI science, with its expertise in data acquisition and interpretation, information modeling and management, integration, decision support, visualization, and dissemination, can help solve many of the grand challenges facing society today and in the future
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