Prof. Dr. rer. nat. Frank Kargl

Prof. Kargl promovierte 2003 und habilitierte sich 2009 an der Universität Ulm. Davor war er unter anderem Mitgründer der Arago AG und in der Netzgruppe des Rechenzentrums / KIZ der Uni Ulm für Netzwerkbetrieb und -sicherheit verantwortlich. Zwischen Ende 2009 und Anfang 2012 war er als Associate Professor in der Gruppe für Distributed and Embedded Security (DIES) der Universität Twente in den Niederlanden tätig, danach bis Januar 2015 als Adjunct Professor. Seit Februar 2012 leitet Prof. Kargl das Institut für Verteilte Systeme an der Uni Ulm. Seit Oktober 2013 fungiert er darüber hinaus als Prodekan der Fakultät für Ingenieurwissenschaften, Informatik und Psychologie.

Forschung

Meine Forschungsinteressen liegen im Bereich mobiler und selbst-organisierender Netzwerke, vor allem der Mobilen Ad-hoc Netzwerke und der Fahrzeug-Fahrzeug-Kommunikation. Ein weiterer Schwerpunkt meiner Arbeit sind Security und Privacy in IT-Systemen. Viele meiner Forschungsprojekte bewegen sich im Überlappungsbereich beider Themen, so z.B. Projekte zu Sicherheit und Privacy von Vehicular Ad-hoc Networks. Andere Arbeiten beschäftigen sich mit der Sicherheit von vernetzten eingebetteten Systemen, z.B. im Kontext der Industrial Control Systems oder bei Building Automation. Weitere Projekte beschäftigen sich mit Secure Cloud Computing, Crypto-Currencies, verteiltem Graphen-basiertem Computing und vielen anderen Themen.

Lehre

Eine ausführliche Auflistung der von mir angebotenen Lehrangebote findet sich hier.

Projekte

Eine Auflistung von aktuellen und früheren Forschungsprojekten des Instituts findet sich hier.

Kontakt

Sprechzeiten

Bitte vereinbaren Sie bei Bedarf einen Termin mit mir über unser Sekretariat (Frau Fehlberg) oder per Email

Publikationen


174.
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Kopp, Henning; Bösch, Christoph und Kargl, Frank
KopperCoin -- A Distributed File Storage with Financial Incentives
ISPEC '16
Herausgeber: Springer,
November 2016

Zusammenfassung: One of the current problems of peer-to-peer-based file storage systems like Freenet is missing participation, especially of storage providers. Users are expected to contribute storage resources but may have little incentive to do so. In this paper we propose KopperCoin, a token system inspired by Bitcoin’s blockchain which can be integrated into a peer-to-peer file storage system. In contrast to Bitcoin, KopperCoin does not rely on a proof of work (PoW) but instead on a proof of retrievability (PoR). Thus it is not computationally expensive and instead requires participants to contribute file storage to maintain the network. Participants can earn digital tokens by providing storage to other users, and by allowing other participants in the network to download files. These tokens serve as a payment mechanism. Thus we provide direct reward to participants contributing storage resources.

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Lukaseder, Thomas; Bradatsch, Leonard; Erb, Benjamin; van der Heijden, Rens W. und Kargl, Frank
A Comparison of TCP Congestion Control Algorithms in 10G Networks
Proceedings of the 41st IEEE Conference on Local Computer Networks (LCN)
November 2016
akzeptiert

Schlüsselwörter: BWNET

Marker: BWNET

Zusammenfassung: The increasing availability of 10G Ethernet network capabilities challenges existing transport layer protocols. As 10G connections gain momentum outside of backbone networks, the choice of appropriate TCP congestion control algorithms becomes even more relevant for networked applications running in environments such as data centers. Therefore, we provide an extensive overview of relevant TCP congestion control algorithms for high-speed environments leveraging 10G. We analyzed and evaluated six TCP variants using a physical network testbed, with a focus on the effects of propagation delay and significant drop rates. The results indicate that of the algorithms compared, BIC is most suitable when no legacy variant is present; CUBIC is suggested otherwise.

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Lukaseder, Thomas; Bradatsch, Leonard; Erb, Benjamin und Kargl, Frank
Setting Up a High-Speed TCP Benchmarking Environment—Lessons Learned
Proceedings of the 41st IEEE Conference on Local Computer Networks (LCN)
November 2016
akzeptiert

Schlüsselwörter: BWNET

Marker: BWNET

Zusammenfassung: There are many high-speed TCP variants with different congestion control algorithms, which are designed for specific settings or use cases. Distinct features of these algorithms are meant to optimize different aspects of network performance, and the choice of TCP variant strongly influences application performance. However, setting up tests to help with the decision of which variant to use can be problematic, as many systems are not designed to deal with high bandwidths, such as 10 Gbps or more. This paper provides an overview of pitfalls and challenges of realistic network analysis to help in the decision making process.

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Meißner, Dominik; Erb, Benjamin; van der Heijden, Rens W.; Lange, Kristin und Kargl, Frank
Mobile Triage Management in Disaster Area Networks Using Decentralized Replication
Proceedings of the Tenth ACM MobiCom Workshop on Challenged Networks
Oktober 2016

Zusammenfassung: In large-scale disaster scenarios, efficient triage management is a major challenge for emergency services. Rescue forces traditionally respond to such incidents with a paper-based triage system, but technical solutions can potentially achieve improved usability and data availability. We develop a triage management system based on commodity hardware and software components to verify this claim. We use a single-hop, ad-hoc network architecture with multi-master replication, a tablet-based device setup and a mobile application for emergency services. We study our system in cooperation with regional emergency services and describe experiences from a field exercise. We show that state-of-the-art commodity technology provides the means necessary to implement a triage management system compatible with existing emergency service procedures, while introducing additional benefits. This work highlights that powerful real-world ad-hoc networking applications do not require unreasonable development effort, as existing tools from distributed systems, like replicating No-SQL databases, can be used successfully.

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van der Heijden, Rens W.; Al-Momani, Ala'a; Kargl, Frank und Abu-Sharkh, Osama M.F.
Enhanced Position Verification for VANETs using Subjective Logic
Proceedings of the 2016 IEEE 84th Vehicular Technology Conference: VTC2016-Fall
Herausgeber: IEEE,
September 2016
akzeptiert

Zusammenfassung: The integrity of messages in vehicular ad-hoc networks has been extensively studied by the research community, resulting in the IEEE~1609.2 standard, which provides typical integrity guarantees. However, the correctness of message contents is still one of the main challenges of applying dependable and secure vehicular ad-hoc networks. One important use case is the validity of position information contained in messages: position verification mechanisms have been proposed in the literature to provide this functionality. A more general approach to validate such information is by applying misbehavior detection mechanisms. In this paper, we consider misbehavior detection by enhancing two position verification mechanisms and fusing their results in a generalized framework using subjective logic. We conduct extensive simulations using VEINS to study the impact of traffic density, as well as several types of attackers and fractions of attackers on our mechanisms. The obtained results show the proposed framework can validate position information as effectively as existing approaches in the literature, without tailoring the framework specifically for this use case.

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Kraft, Robin; Erb, Benjamin; Mödinger, David und Kargl, Frank
Using Conflict-Free Replicated Data Types for Serverless Mobile Social Applications
Proceedings of the 8th ACM International Workshop on Hot Topics in Planet-scale mObile computing and online Social neTworking
Juli 2016

Zusammenfassung: A basic reason for backend systems in mobile application architectures is the centralized management of state. Mobile clients synchronize local states with the backend in order to maintain an up-to-date view of the application state. As not all mobile social applications require strong consistency guarantees, we survey an alternative approach using special data structures for mobile applications. These data structures only provide eventual consistency, but allow for conflict-free replication between peers. Our analysis collects the requirements of social mobile applications for being suitable for this approach. Based on exemplary mobile social applications, we also point out the benefits of serverless architecture or architectures with a thin backend layer.

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Bösch, Christoph; Erb, Benjamin; Kargl, Frank; Kopp, Henning und Pfattheicher, Stefan
Tales from the Dark Side: Privacy Dark Strategies and Privacy Dark Patterns
Proceedings on Privacy Enhancing Technologies, 2016(4)
Juli 2016

Zusammenfassung: Privacy strategies and privacy patterns are fundamental concepts of the privacy-by-design engineering approach. While they support a privacy-aware development process for IT systems, the concepts used by malicious, privacy-threatening parties are generally less understood and known. We argue that understanding the ``dark side'', namely how personal data is abused, is of equal importance. In this paper, we introduce the concept of privacy dark strategies and privacy dark patterns and present a framework that collects, documents, and analyzes such malicious concepts. In addition, we investigate from a psychological perspective why privacy dark strategies are effective. The resulting framework allows for a better understanding of these dark concepts, fosters awareness, and supports the development of countermeasures. We aim to contribute to an easier detection and successive removal of such approaches from the Internet to the benefit of its users.

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Al-Momani, Ala'a; Kargl, Frank und Waldschmidt, Christian
Physical Layer-Based Message Authentication in VANETs
4th GI/ITG KuVS Fachgespräch Inter-Vehicle Communication, Berlin, Germany
März 2016

Marker: AlaaAlMomani

Zusammenfassung: Authenticating legitimate nodes is a major concern of the envisioned vehicular networks. To achieve this, standards and literature propose to use asymmetric cryptographic mechanisms which generate significant overheads in terms of time and power consumption. In this paper, we address this problem and we propose a novel idea of exploiting physical layer characteristics to rely on them for re-authenticating future beacons after verifying the first one cryptographically. Despite the challenges in such high mobility networks, possible concrete approaches to start the evaluation of our scheme are presented. Our approaches are inspired by the vehicular channel related work conclusions which give signs of future success to our scheme in this critical field.

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Dietzel, Stefan; Gürtler, Julian und Kargl, Frank
A resilient in-network aggregation mechanism for VANETs based on dissemination redundancy
Ad Hoc Networks, 37, Part 1:101 - 109
Februar 2016
ISSN: 1570-8705

Schlüsselwörter: Multi-hop communication

Marker: FrankKargl, StefanDietzel, F3

Zusammenfassung: Abstract In the field of Vehicular Ad-hoc Networks (VANETs), traffic efficiency applications, such as traffic information systems, are particularly challenging, because they often require the dissemination of information within large geographic areas. Forwarding information over multiple hops is a necessity, and due to the amount of available information, the available wireless capacity is easily exhausted. In-network aggregation protocols are often used to cope with wireless channel restrictions. Their aim is to collaboratively create summaries of traffic information and other information items as information is disseminated within the network. But in-network aggregation is challenging form a security perspective: insider attackers may be able to alter not only their own observations but also modify already aggregated information, or they may introduce false aggregates. As a result, wrong routing decisions may be taken, or drivers may engage in dangerous driving maneuvers. Existing security mechanisms for in-network aggregation often introduce considerable additional overhead, resulting from cryptographic proofs, such as signatures. In this work, we follow a different approach: we design a resilient aggregation mechanism that leverages already existing communication redundancy and combines it with data consistency checks to identify and filter false aggregates information. Our security mechanism introduces limited additional overhead, and simulation results show that at least 20% attacker vehicles can be tolerated by our mechanism.

Bemerkung: Special Issue on Advances in Vehicular Networks

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Förster, David; Kargl, Frank und Löhr, Hans
PUCA: A pseudonym scheme with strong privacy guarantees for vehicular ad-hoc networks
Ad Hoc Networks, 37, Part 1:122 - 132
Februar 2016
ISSN: 1570-8705

Schlüsselwörter: Anonymous credentials

Marker: FrankKargl, F3

Zusammenfassung: Abstract Pseudonym certificates are the state-of-the-art approach for secure and privacy-friendly message authentication in vehicular ad-hoc networks. However, most of the proposed pseudonym schemes focus on privacy among participants. Privacy towards backend providers is usually (if at all) only protected by separation of responsibilities. The protection can be overridden, when the entities collaborate, e.g. when revocation of long-term credentials is required. This approach puts the users' privacy at risk, if the backend systems are not fully trusted. We propose PUCA -- a scheme that provides full anonymity for honest users, even against colluding backend providers. The scheme uses anonymous credentials for authentication with the backend, while leaving the communication among vehicles and with road side units unchanged and in compliance with existing standards. For removal of misbehaving vehicles from the system, we leverage a privacy-friendly revocation mechanism, that does not require resolution of pseudonyms. With our scheme, we demonstrate that strong and verifiable privacy protection in vehicular networks can be achieved, while fulfilling common security requirements, such as sybil-resistance and revocation.

Bemerkung: Special Issue on Advances in Vehicular Networks

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Dietzel, Stefan; van der Heijden, Rens W.; Petit, Jonathan und Kargl, Frank
Context-adaptive Detection of Insider Attacks in VANET Information Dissemination Schemes
Vehicular Networking Conference (VNC), 2015 IEEE , Seite 293-300.
Herausgeber: IEEE, Kyoto, Japan
Dezember 2015

Marker: FrankKargl, RensVanDerHeijden, StefanDietzel, F3

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Förster, David; Löhr, Hans und Kargl, Frank
Decentralized Enforcement of k-Anonymity for Location Privacy Using Secret Sharing
Vehicular Networking Conference (VNC), 2015 IEEE , Seite 285-292.
Herausgeber: IEEE, Kyoto, Japan
Dezember 2015

Marker: FrankKargl, F3

162.
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Al-Momani, Ala'a; Kargl, Frank; Waldschmidt, Christian; Moser, Steffen und Slomka, Frank
Wireless Channel-Based Message Authentication
Vehicular Networking Conference (VNC), 2015 IEEE , Seite 277-280.
Herausgeber: IEEE, Kyoto, Japan
Dezember 2015

Marker: AlaaAlMomani, FrankKargl, F3

Zusammenfassung: Inter-vehicle communication has attracted a lot of attention in the past. A major concern is the security and especially the integrity and authenticity of messages. Current standards and proposals in literature leverage asymmetric cryptographic mechanisms to achieve this, which is costly both in terms of consumed computational power, bandwidth, and introduced delay. We present a novel idea to use physical characteristics of the wireless channel to verify subsequent messages after initial trust in a first message has been established cryptographically. In this paper, we sketch the concept and provide a first evaluation on its potential for saving named resources.

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Petit, Jonathan; Broekhuis, Djurre; Feiri, Michael und Kargl, Frank
Connected Vehicles: Surveillance Threat and Mitigation
Black Hat Europe
November 2015

Marker: FrankKargl, F3, PRIPARE

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Petit, Jonathan; Stottelaar, Bas; Feiri, Michael und Kargl, Frank
Remote Attacks on Automated Vehicles Sensors: Experiments on Camera and LiDAR
Black Hat Europe
November 2015

Marker: FrankKargl, F3

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Kleber, Stephan; Unterstein, Florian; Matousek, Matthias; Kargl, Frank; Slomka, Frank und Hiller, Matthias
Design of the Secure Execution PUF-based Processor (SEPP)
Workshop on Trustworthy Manufacturing and Utilization of Secure Devices, TRUDEVICE 2015
September 2015

Marker: FrankKargl, StephanKleber, MatthiasMatousek

Zusammenfassung: A persistent problem with program execution is its vulnerability to code injection attacks. Equally unsolved is the susceptibility of software to reverse engineering, which undermines code confidentiality. We propose an approach that solves both kinds of security problems by employing instruction-level code encryption combined with the use of a physical unclonable function (PUF). Our Secure Execution PUF-based Processor (SEPP) architecture is designed to minimize the attack surface, as well as the performance impact, and requires no significant changes to the software development process. Our approach supports distributed systems, as the secure execution environment needs not be physically available to the developer.

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Förster, David; Löhr, Hans; Zibuschka, Jan und Kargl, Frank
REWIRE - Revocation Without Resolution: A Privacy-Friendly Revocation Mechanism for Vehicular Ad-Hoc Networks
In Conti, Mauro and Schunter, Matthias and Askoxylakis, Ioannis, Editor, Trust and Trustworthy Computing Band 9229 aus Lecture Notes in Computer Science , Seite 193-208.
Herausgeber: Springer International Publishing,
August 2015
ISBN: 978-3-319-22845-7

Marker: FrankKargl, DavidFoerster, PRESERVE, F3

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Kleber, Stephan; Unterstein, Florian; Matousek, Matthias; Kargl, Frank; Slomka, Frank und Hiller, Matthias
Secure Execution Architecture based on PUF-driven Instruction Level Code Encryption
IACR,
Juli 2015

Marker: FrankKargl, StephanKleber, MatthiasMatousek

Zusammenfassung: A persistent problem with program execution, despite numerous mitigation attempts, is its inherent vulnerability to the injection of malicious code. Equally unsolved is the susceptibility of firmware to reverse engineering, which undermines the manufacturer's code confidentiality. We propose an approach that solves both kinds of security problems employing instruction-level code encryption combined with the use of a physical unclonable function (PUF). Our novel Secure Execution PUF-based Processor (SEPP) architecture is designed to minimize the attack surface, as well as performance impact, and requires no significant changes to the development process. This is possible based on a tight integration of a PUF directly into the processor's instruction pipeline. Furthermore, cloud scenarios and distributed embedded systems alike inherently depend on remote execution; our approach supports this, as the secure execution environment needs not to be locally available at the developers site. We implemented an FPGA-based prototype based on the OpenRISC Reference Platform. To assess our results, we performed a security analysis of the processor and evaluated the performance impact of the encryption. We show that the attack surface is significantly reduced compared to previous approaches while the performance penalty is at a reasonable factor of about 1.5.

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Erb, Benjamin und Kargl, Frank
A Conceptual Model for Event-sourced Graph Computing
Proceedings of the 9th ACM International Conference on Distributed Event-Based Systems aus DEBS '15 , Seite 352--355.
Herausgeber: ACM, New York, NY, USA
Juni 2015
ISBN: 978-1-4503-3286-6

Schlüsselwörter: batch processing, event processing, event sourcing, event-driven architecture, graph computing

Marker: BenjaminErb, FrankKargl, SIDGRAPH

155.
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Förster, David; Kargl, Frank und Löhr, Hans
A Framework for Evaluating Pseudonym Strategies in Vehicular Ad-hoc Networks
Proceedings of the 8th ACM Conference on Security & Privacy in Wireless and Mobile Networks aus WiSec '15 , Seite 19:1--19:6.
Herausgeber: ACM, New York, NY, USA
Juni 2015
ISBN: 978-1-4503-3623-9

Schlüsselwörter: location privacy, pseudonym systems, vehicular ad-hoc networks

Marker: FrankKargl, DavidFoerster, PRESERVE, F3

154.
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Feiri, Michael; Pielage, Rolf; Petit, Jonathan; Zannone, Nicola und Kargl, Frank
Pre-Distribution of Certificates for Pseudonymous Broadcast Authentication in VANET
Vehicular Technology Conference (VTC Spring), 2015 IEEE 81st , Seite 1-5.
Mai 2015

Schlüsselwörter: cryptography;telecommunication security;vehicular ad hoc networks;VANET;certificate management;certificate pre-distribution;communication overhead;cryptographic packet loss;pseudonymous broadcast authentication;vehicular networks;Bandwidth;Cryptography;Privacy;Vehicles;Vehicular ad hoc networks;Wireless communication

Marker: FrankKargl, PRESERVE, F3

153.
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Dietzel, Stefan; Peter, Andreas und Kargl, Frank
Secure Cluster-Based In-Network Information Aggregation for Vehicular Networks
Vehicular Technology Conference (VTC Spring), 2015 IEEE 81st , Seite 1-5.
IEEE
Glasgow, U.K.
Mai 2015

Schlüsselwörter: estimation theory;telecommunication security;telecommunication traffic;vehicular ad hoc networks;bandwidth-efficient integrity proofs;hyperloglog estimators;in-network information aggregation;safety enhancements;secure cluster;security mechanism;traffic efficiency enhancements;vehicular ad hoc networks;velocity-based vehicle clustering;Aggregates;Bandwidth;Data structures;Public key;Registers;Vehicles

Marker: FrankKargl, StefanDietzel, PRESERVE, F3

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Caselli, Marco; Zambon, Emmanuele und Kargl, Frank
Sequence-aware Intrusion Detection in Industrial Control Systems
Proceedings of the 1st ACM Workshop on Cyber-Physical System Security aus CPSS Workshop - AsiaCCS'15 , Seite 13--24.
Herausgeber: ACM, New York, NY, USA
April 2015
ISBN: 978-1-4503-3448-8

Schlüsselwörter: cyber-physical system, intrusion detection system, semantic attack, sequence attack

Marker: FrankKargl, CRISALIS

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Kleber, Stephan; van der Heijden, Rens W.; Kopp, Henning und Kargl, Frank
Terrorist fraud resistance of distance bounding protocols employing physical unclonable functions
Networked Systems (NetSys), 2015 International Conference and Workshops on , Seite 1-8.
Herausgeber: IEEE,
März 2015

Schlüsselwörter: public key cryptography;radio networks;telecommunication security;PUF-analogue;SIMPL systems;distance bounding protocols;physical unclonable functions;public-key cryptography;security model;security problems;terrorist fraud resistance;wireless communication;Computational modeling;Protocols;Terrorism;Time factors;Timing

Marker: FrankKargl, StephanKleber, HenningKopp, RensVanDerHeijden

Zusammenfassung: Distance bounding protocols (DBPs) are security protocols that aim to limit the maximum possible distance between two partners in a wireless communication. This enables to ensure locality of interaction between two devices. Despite numerous proposed protocols, recent analyses of DBPs have shown the majority of them to be susceptible to attacks. Most prominent among the unsolved security problems of DBPs is terrorist fraud. This type of attack involves collaboration with a legitimate device, after which the attacker can successfully execute the protocol. We show how terrorist fraud can be prevented by replacing shared secrets - commonly used in classical DBPs - with physical unclonable functions (PUFs). Our new approach can be integrated in all current DBPs with minor modifications. We offer two alternate designs: One utilizing challenge-response PUFs and another using so-called SIMPL systems, a PUF-analogue to public-key cryptography. We use a security model proposed by previous work to demonstrate security of our scheme.

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Caselli, Marco; Zambon, Emmanuele; Petit, Jonathan und Kargl, Frank
Modeling message sequences for intrusion detection in industrial control systems
In Rice, M. and Shenoi, S., Editor, Proceedings of the Ninth IFIP 11.10 International Conference aus Critical Infrastructure Protection IX , Seite 49--71.
Herausgeber: Springer Verlag, Arlington, Virginia, US
März 2015

Schlüsselwörter: Industrial control systems, sequence attacks, intrusion detection

Marker: FrankKargl, CRISALIS

Zusammenfassung: Compared with standard information technology systems, industrial control systems show more consistent and regular communications patterns. This characteristic contributes to the stability of controlled processes in critical infrastructures such as power plants, electric grids and water treatment facilities. However, Stuxnet has demonstrated that skilled attackers can strike critical infrastructures by leveraging knowledge about these processes. Sequence attacks subvert infrastructure operations by sending misplaced industrial control system messages. This chapter discusses four main sequence attack scenarios against industrial control systems. Real Modbus, Manufacturing Message Specification and IEC 60870-5-104 traffic samples were used to test sequencing and modeling techniques for describing industrial control system communications. The models were then evaluated to verify the feasibility of identifying sequence attacks. The results create the foundation for developing ?sequence-aware? intrusion detection systems.

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