Informationen des Universitätsrechenzentrums

Informationen des Universitätsrechenzentrums:MyURZ - das persönliche URZ-Profil DFN-AAI - Authentifizierungs- und Autorisierungs-Infrastruktur im Deutschen Forschungsnetz Windows Vista am Campus - Stand und Perspektive Überarbeitetes Corporate Design und Web-Autorensystem Sichere E-Mail durch persönliche Zertifikate Softwareausstattung der Ausbildungspools Neues aus der UB Kurzinformationen: Neu: 'URZ-Information' - Das Wichtigste in Kürze, Neues Funknetz 'web-psk', MeetingPlace - Rich Media Conferencing, Schwache SSH-Schlüssel, Neues Verfahren für Kernel-Updates in Linux-Systemen, Campus Mobil - WLAN-Telefon 7921 Software-News: Firefox 2 auf den Linux-Rechnern des URZ, Upgrade der OpenAFS-Version für Windows, Upgrade der OpenAFS-Version für Linux, Migration auf Scientific Linux 5.1

Informationen des Universitätsrechenzentrums:Projekt SECNet - Security Enhanced CampusNet Lösungen für personenunabhängige E-Mail-Adressen Windows Vista an der TU Chemnitz Admindienste in MyURZ Vidkon - ein Schritt in Richtung Multimedia-Campus 'Mobile Connect' = Parallelruf am Handy Kurzinformationen: Neue Version von Webmail in Betrieb, Windows-Applikationsserver (WAPPS) erneuert, Betrieb der Web-Cache Server wird eingestellt, Virtueller Computeserver, Migration auf Scientific Linux 4.7, Neues im IT-Service der UB Software-News: Bedarf an Geodaten-Software?, Bedarfsumfrage: PGI Cluster Development Kit für Linux, Mathematica Player verfügbar, Neue Softwarehandbücher

As a consequence of the highly increasing cross-linking of computer systems in computer networks, the possibilities for accessing programs operated at these machines is becoming more and more independent from the possibilities of having physical access to them. Thus the former existing physical access controls have to be replaced by logical access controls which ensure that computer systems are only used for the intended purpose and that the stored data are handled securely and confidentially. The efficiency of such logical protection mechanism is verified by applying software security tests. During such tests it is proved whether security functions can be bypassed especially by exploiting software errors. In this diploma thesis approaches for the automation of software security tests are examined regarding their effectiveness and applicability. The results are used to introduce a requirement and evaluation model for the qualitative analysis of such security evaluation automation approaches. Additionally, the assertion is made that a highly automated software security evaluation is not a sensible development goal referring to the estimated cost-benefit ratio which is gained by trying to realise this goal. Based on this assertion, this diploma thesis discusses how to join the capabilities of a human tester and a software evaluation assistance system in an efficient test process. Based on this considerations, the design and implementation of a software security evaluation system which has been developed prototypically for this diploma thesis is described. This system significantly involves the human tester in the evaluation process but provides approaches for automation where possible. Furthermore this proof-of-concept prototype is evaluated regarding its practical applicability. / Durch die zunehmende starke Vernetzung von Computertechnologie wird die Möglichkeit des Zugriffs auf einzelne Computersysteme und den darauf ablaufenden Programmen zunehmend ebenso stark unabhängig von den physischen Zugangsmöglichkeiten des Zugreifenden zu diesen Systemen. Diese wegfallenden physischen Zugangsbarrieren müssen deshalb durch logische Zugriffsbeschränkungen ersetzt werden, die sicherstellen, dass Computersysteme nur zu den vorgesehen Zwecken verwendet und die darin gespeicherten Daten sicher und vertraulich verarbeitet werden. Die Wirksamkeit dieser logischen Schutzmechanismen wird mit Hilfe von s.g. Softwaresicherheitstests verifiziert. Dabei wird insbesondere überprüft, inwiefern Schutzfunktionen durch Zuhilfenahme von in der Software vorhandenen Programmfehlern umgangen werden können. Diese Diplomarbeit überprüft bestehende Ansätze für die Automatisierung solcher Sicherheitstests hinsichtlich ihrer Wirksamkeit und Anwendbarkeit. Aus den Resultaten dieser Untersuchung wird ein allgemeines Anforderungs- und Bewertungsmodell entwickelt, welches die qualitative Bewertung von Ansätzen zur Sicherheitstestautomatisierung zulässt. Desweiteren wird die Behauptung aufgestellt, dass die Forderung nach einer zu starken Automatisierung des Testverfahrens sich ungünstig gegenüber des Kosten-Nutzen-Verhältnisses auswirkt, welches bei der Realisierung dieser Forderungen zu erwarten ist. Darauf aufbauend versucht die Diplomarbeit abzugrenzen, wie sich die Fähigkeiten des menschlichen Testers und eines teilautomatisierbaren Softwaresystems effizient in einem Sicherheitstestprozess verbinden lassen. Basierend auf diesen Betrachtungen wird beschrieben, wie ein Sicherheitsevaluierungssystem, welches prototypisch für diese Diplomarbeit entwickelt wurde, den Menschen zur Erstellung von Testalgorithmen einbindet aber, wenn dies zweckmäßig ist, Automatisierungen ermöglicht. Dieses System wird daraufhin auf seine praktische Anwendbarkeit untersucht.

Informationen des Universitätsrechenzentrums mit Jahresrückblick 2006 zu den aktuellen Projekten und Diensten des URZ

Informationen des Universitätsrechenzentrums mit Jahresrückblick 2006 zu den aktuellen Projekten und Diensten des URZ:Jahresrückblick 2006 Windows-Softwareausstattung der Computerpools im Sommersemester 2007 Software-News Kurzinformationen

Dynamic address assignment is one of the most important features in wireless ad hoc networks if nodes should be enabled to join and to work in the network by automatically configuring all necessary settings. Different approaches have been developed throughout the last years to achieve this objective of Dynamic Address Autoconfiguration but research primarily focused on efficiency and correctness, less on security issues. Whereas Duplicate Address Detection has become reliable in commonplace scenarios, it is still relatively easy to suspend the whole network functionality in extraordinary situations within the boundaries of a Dynamic Address Configuration Protocol. In this paper, we therefore want to point out shortcomings and weaknesses in existing protocol solutions which address dynamic IP address assignment. We concentrate on a leader-based approach called ODACP and want to propose several solutions which improve the original protocol in such a way that it is safer against malicious host activities. Finally, we will demonstrate the improvements of our solution in a separate test scenario.

Die "Mitteilungen des URZ" informieren die Nutzer des Universitätsrechenzentrums der TU Chemnitz umfassend über neue Dienste und Projekte, vermitteln ggf. Hintergrundwissen und dienen der Berichterstattung.

Prognostiziert durch Konzepte der Industrie 4.0 und den Cyber-Physischen-Systemen, können autonome Systeme zukünftig dynamisch auf Datenquellen in ihrer Umgebung zugreifen. Während die gemeinsame Nutzung solcher Datenquellen ein enormes Performanzpotenzial bietet, stellt die benötigte Systemarchitektur vorherrschende Sicherheitsprozesse vor neue Herausforderungen. Die vorliegende Arbeit motiviert zunächst, dass diese nur zur Laufzeit des Systems adressiert werden könne, bevor sie daraus zwei zentrale Ziele ableitet und verfolgt. Zum einen wird ein Beschreibungsmodel für die Darstellung von Fehlercharakteristika gemeinsam genutzter Daten vorgestellt. Dieses generische Fehlermodell erlaubt es zum anderen eine Sicherheitsanalyse zu definieren, die eine spezifische, dynamische Systemkomposition zur Laufzeit mit Hinblick auf die zu erwartenden Unsicherheiten bewerten kann. Die als Region of Safety betitelte Analysestrategie erlaubt, in Kombination mit dem generischen Fehlermodell, die Sicherheit der auf gemeinsam genutzten Daten basierenden Kollisionsvermeidungsstrategie zweier Roboter noch zur Designzeit zu garantieren, obwohl die spezifischen Fehlercharakteristika der Daten erst zur Laufzeit bekannt werden.:List of Acronyms List of Theorems List of Definitions List of Figures List of Tables 1. Introduction – Safety in Future Smart Industries 1.1. The Example of Smart Warehouses 1.2. Functional Safety Standards 1.2.1. Overview of Functional Safety Standards 1.2.2. IEC 61508 1.3. Scope of this Thesis 1.3.1. Objectives 1.3.2. Contributions 1.3.3. Outline 1.4. Related Publications by the Author 1.5. Mathematical Notation 2. State of the Art 2.1. State of the Art in Run-Time Safety Assessment 2.1.1. Approaches at the Functional Level 2.1.2. Approaches at the Technical Level 2.1.3. Conclusions 2.2. State of the Art in Failure Modeling 2.2.1. The Definition of (Sensor) Failure Model 2.2.2. Interval-Based Failure Modeling 2.2.3. Distribution-Based Failure Modeling 2.2.4. Failure-Type-Based Failure Modeling 2.2.5. Conclusions 2.3. Conclusions from the State of the Art 3. Generic Failure Model 3.1. Defining the Generic Failure Model 3.1.1. Time- and Value-Correlated Random Distribution 3.1.2. A Failure Type’s Failure Amplitudes 3.1.3. A Failure Type’s State Function 3.1.4. Polynomial Representation of a Failure Type 3.1.5. Discussion on the Fulfillment of the Predefined Criteria 3.2. Converting a Generic Failure Model to an Interval 3.2.1. Converting a Time- and Value-Correlated Random Distribution 3.2.2. A Failure Type’s Interval 3.3. Processing Chain for Generating Generic Failure Models 3.3.1. Identifying Failure Types 3.3.2. Parameterizing Failure Types 3.3.3. Confidence Calculation 3.4. Exemplary Application to Artificial Failure Characteristics 3.4.1. Generating the Artificial Data Set – Manually Designing GFMs 3.4.2. Identifying Failure Types 3.4.3. Parameterizing Failure Types 3.4.4. Confidence Calculation 3.4.5. Comparison to State-of-the-Art Models 3.5. Summary 4. Region of Safety 4.1. Explicitly Modeling Uncertainties for Dynamically Composed Systems 4.2. Regions of Safety for Dynamically Composed Systems 4.2.1. Estimating Regions of Attraction in Presence of Uncertainty 4.2.2. Introducing the Concept of Region of Safety 4.2.3. Discussion on the Fulfillment of the Predefined Criteria 4.3. Evaluating the Concept of Region of Safety 4.3.1. Defining the Scenario and Considered Uncertainties 4.3.2. Designing a Control Lyapunov Function 4.3.3. Determining an Appropriate Value for λc 4.3.4. The Effect of Varying Sensor Failures on Regions of Safety 4.4. Summary 5. Evaluation and Integration 5.1. Multi-Robot Collision Avoidance 5.1.1. Assumptions 5.1.2. Design of the Circle and Navigation Scenarios 5.1.3. Kinematics 5.1.4. Control Policy 5.1.5. Intention Modeling by Model Uncertainty 5.1.6. Fusing Regions of Safety of Multiple Stability Points 5.2. Failure Modeling for Shared Data – A Marker Detection Failure Model 5.2.1. Data Acquisition 5.2.2. Failure Model Generation 5.2.3. Evaluating the Quality of the Failure Model 5.3. Safe Handling of Shared Data in a Collision Avoidance Strategy 5.3.1. Configuration for Region of Safety Estimation 5.3.2. Estimating Regions of Safety 5.3.3. Evaluation Using the Circle Scenario 5.3.4. Evaluation Using the Navigation Scenario 5.4. Summary 6. Conclusions and Future Work 6.1. Summary 6.2. Limitations and Future Work 6.2.1. Limitations and Future Work on the Generic Failure Model 6.2.2. Limitations and Future Work on Region of Safety 6.2.3. Future Work on Safety in Dynamically Composed Systems Appendices A. Defining Factors of Risk According to IEC 61508 B. Evaluation Results for the Identification Stage C. Overview of Failure Amplitudes of Marker Detection Results Bibliography / The concepts of Cyber-Physical-Systems and Industry 4.0 prognosticate autonomous systems to integrate sources of shared data dynamically at their run-time. While this promises substantial increases in their performance, the openness of the required system architecture poses new challenges to processes guaranteeing their safety. This thesis firstly motivates that these can be addressed only at their run-time, before it derives and pursues two corresponding goals. Firstly, a model for describing failure characteristics of shared data is presented. Secondly, this Generic Failure Model is built upon to define a run-time safety assessment methodology that enables analyzing dynamic system compositions integrating shared data with respect to the expected uncertainties at run-time. This analysis strategy, entitled Region of Safety, allows in combination with the generic failure model to guarantee the safety of robots sharing position data for collision avoidance already at design-time, although specific failure characteristics become available only at run-time.:List of Acronyms List of Theorems List of Definitions List of Figures List of Tables 1. Introduction – Safety in Future Smart Industries 1.1. The Example of Smart Warehouses 1.2. Functional Safety Standards 1.2.1. Overview of Functional Safety Standards 1.2.2. IEC 61508 1.3. Scope of this Thesis 1.3.1. Objectives 1.3.2. Contributions 1.3.3. Outline 1.4. Related Publications by the Author 1.5. Mathematical Notation 2. State of the Art 2.1. State of the Art in Run-Time Safety Assessment 2.1.1. Approaches at the Functional Level 2.1.2. Approaches at the Technical Level 2.1.3. Conclusions 2.2. State of the Art in Failure Modeling 2.2.1. The Definition of (Sensor) Failure Model 2.2.2. Interval-Based Failure Modeling 2.2.3. Distribution-Based Failure Modeling 2.2.4. Failure-Type-Based Failure Modeling 2.2.5. Conclusions 2.3. Conclusions from the State of the Art 3. Generic Failure Model 3.1. Defining the Generic Failure Model 3.1.1. Time- and Value-Correlated Random Distribution 3.1.2. A Failure Type’s Failure Amplitudes 3.1.3. A Failure Type’s State Function 3.1.4. Polynomial Representation of a Failure Type 3.1.5. Discussion on the Fulfillment of the Predefined Criteria 3.2. Converting a Generic Failure Model to an Interval 3.2.1. Converting a Time- and Value-Correlated Random Distribution 3.2.2. A Failure Type’s Interval 3.3. Processing Chain for Generating Generic Failure Models 3.3.1. Identifying Failure Types 3.3.2. Parameterizing Failure Types 3.3.3. Confidence Calculation 3.4. Exemplary Application to Artificial Failure Characteristics 3.4.1. Generating the Artificial Data Set – Manually Designing GFMs 3.4.2. Identifying Failure Types 3.4.3. Parameterizing Failure Types 3.4.4. Confidence Calculation 3.4.5. Comparison to State-of-the-Art Models 3.5. Summary 4. Region of Safety 4.1. Explicitly Modeling Uncertainties for Dynamically Composed Systems 4.2. Regions of Safety for Dynamically Composed Systems 4.2.1. Estimating Regions of Attraction in Presence of Uncertainty 4.2.2. Introducing the Concept of Region of Safety 4.2.3. Discussion on the Fulfillment of the Predefined Criteria 4.3. Evaluating the Concept of Region of Safety 4.3.1. Defining the Scenario and Considered Uncertainties 4.3.2. Designing a Control Lyapunov Function 4.3.3. Determining an Appropriate Value for λc 4.3.4. The Effect of Varying Sensor Failures on Regions of Safety 4.4. Summary 5. Evaluation and Integration 5.1. Multi-Robot Collision Avoidance 5.1.1. Assumptions 5.1.2. Design of the Circle and Navigation Scenarios 5.1.3. Kinematics 5.1.4. Control Policy 5.1.5. Intention Modeling by Model Uncertainty 5.1.6. Fusing Regions of Safety of Multiple Stability Points 5.2. Failure Modeling for Shared Data – A Marker Detection Failure Model 5.2.1. Data Acquisition 5.2.2. Failure Model Generation 5.2.3. Evaluating the Quality of the Failure Model 5.3. Safe Handling of Shared Data in a Collision Avoidance Strategy 5.3.1. Configuration for Region of Safety Estimation 5.3.2. Estimating Regions of Safety 5.3.3. Evaluation Using the Circle Scenario 5.3.4. Evaluation Using the Navigation Scenario 5.4. Summary 6. Conclusions and Future Work 6.1. Summary 6.2. Limitations and Future Work 6.2.1. Limitations and Future Work on the Generic Failure Model 6.2.2. Limitations and Future Work on Region of Safety 6.2.3. Future Work on Safety in Dynamically Composed Systems Appendices A. Defining Factors of Risk According to IEC 61508 B. Evaluation Results for the Identification Stage C. Overview of Failure Amplitudes of Marker Detection Results Bibliography

Informationen des Universitätsrechenzentrums mit Jahresrückblick 2007 zu den aktuellen Projekten und Diensten des URZ