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Thomas Clausen

Bio: Thomas Clausen is an academic researcher from École Polytechnique. The author has contributed to research in topics: Optimized Link State Routing Protocol & Routing protocol. The author has an hindex of 32, co-authored 124 publications receiving 12924 citations. Previous affiliations of Thomas Clausen include IEEE Computer Society & University of Paris-Sud.


Papers
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12 Aug 2014
TL;DR: In this paper, the authors analyze common security threats of the Optimized LinkState Routing Protocol version 2 (OLSRv2) and describe their potential impacts on MANETs.
Abstract: This document analyzes common security threats of the Optimized Link State Routing Protocol version 2 (OLSRv2) and describes their potential impacts on Mobile Ad Hoc Network (MANET) operations. It then analyzes which of these security vulnerabilities can be mitigated when using the mandatory-to-implement security mechanisms for OLSRv2, and how the vulnerabilities are mitigated.

2 citations

Journal ArticleDOI
TL;DR: In this article, an abstract look at the algorithms that constitute the Optimized Link State Routing Protocol version 2 (OLSRv2), and identifies for each protocol element the possible vulnerabilities and attacks, in a certain way, provides a "cookbook" for how to best attack an operational OLSRv2 network.
Abstract: Mobile Ad hoc NETworks (MANETs) are leaving the confines of research laboratories, to find place in real-world deployments. Outside specialized domains (military, vehicular, etc.), city-wide communitynetworks are emerging, connecting regular Internet users with each other, and with the Internet, via MANETs. Growing to encompass more than a handful of "trusted participants", the question of preserving the MANET network connectivity, even when faced with careless or malicious participants, arises, and must be addressed. A first step towards protecting a MANET is to analyze the vulnerabilities of the routing protocol, managing the connectivity. By understanding how the algorithms of the routing protocol operate, and how these can be exploited by those with ill intent, countermeasures can be developed, readying MANETs for wider deployment and use. This paper takes an abstract look at the algorithms that constitute the Optimized Link State Routing Protocol version 2 (OLSRv2), and identifies for each protocol element the possible vulnerabilities and attacks -- in a certain way, provides a "cookbook" for how to best attack an operational OLSRv2 network, or for how to proceed with developing protective countermeasures against these attacks.

2 citations

16 Sep 2010
TL;DR: A critical look at the state of advancement of the RPL routing protocol is taken, a brief algorithmic description of the protocol is provided, and areas where further efforts are required are discussed, including the lack of a proper broadcast mechanism.
Abstract: Recent trends in Wireless Sensor Networks (WSNs) have suggested converging to such being IPv6-based. to this effect, the Internet Engineering Task Force has chartered a Working Group to develop a routing protocol specification, enabling IPv6-based multi-hop Wireless Sensor Networks. This routing protocol, denoted RPL, has been under development for approximately a year, and this memorandum takes a critical look at the state of advancement hereof: it provides a brief algorithmic description of the protocol, and discusses areas where -- in the authors view -- further efforts are required in order for the protocol to become a viable candidate for general use in WSNs. Among these areas is the lack of a proper broadcast mechanism. This memorandum suggests two such broadcast mechanisms, both aiming at (i) exploiting the existing routing state of RPL, while (ii) requiring no additional state maintenance, and studies the performance of RPL and of these suggested mechanisms.

2 citations

Journal ArticleDOI
TL;DR: In this paper, a unified and centralized-monitoring-free architecture achieving both autoscaling and load-balancing, reducing operational overhead while increasing response time performance, is proposed, which can achieve asymptotic zero-wait time with high (and controlable) probability.
Abstract: Cloud architectures achieve scaling through two main functions: (i) load-balancers, which dispatch queries among replicated virtualized application instances, and (ii) autoscalers, which automatically adjust the number of replicated instances to accommodate variations in load patterns. These functions are often provided through centralized load monitoring, incurring operational complexity. This article introduces a unified and centralized-monitoring-free architecture achieving both autoscaling and load-balancing, reducing operational overhead while increasing response time performance. Application instances are virtually ordered in a chain, and new queries are forwarded along this chain until an instance, based on its local load, accepts the query. Autoscaling is triggered by the last application instance, which inspects its average load and infers if its chain is under- or over-provisioned. An analytical model of the system is derived, and proves that the proposed technique can achieve asymptotic zero-wait time with high (and controlable) probability. This result is confirmed by extensive simulations, which highlight close-to-ideal performance in terms of both response time and resource costs.

2 citations

12 Jul 2013
TL;DR: This specification updates the Optimized Link State Routing Protocol version 2 (OLSRv2) with an optimization to improve the selection of routing MPRs.
Abstract: This specification updates the Optimized Link State Routing Protocol version 2 (OLSRv2) with an optimization to improve the selection of routing MPRs The optimization retains full interoperability between implementations of OLSRv2 with and without this optimization

2 citations


Cited by
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Journal ArticleDOI
TL;DR: An overview of the Internet of Things with emphasis on enabling technologies, protocols, and application issues, and some of the key IoT challenges presented in the recent literature are provided and a summary of related research work is provided.
Abstract: This paper provides an overview of the Internet of Things (IoT) with emphasis on enabling technologies, protocols, and application issues. The IoT is enabled by the latest developments in RFID, smart sensors, communication technologies, and Internet protocols. The basic premise is to have smart sensors collaborate directly without human involvement to deliver a new class of applications. The current revolution in Internet, mobile, and machine-to-machine (M2M) technologies can be seen as the first phase of the IoT. In the coming years, the IoT is expected to bridge diverse technologies to enable new applications by connecting physical objects together in support of intelligent decision making. This paper starts by providing a horizontal overview of the IoT. Then, we give an overview of some technical details that pertain to the IoT enabling technologies, protocols, and applications. Compared to other survey papers in the field, our objective is to provide a more thorough summary of the most relevant protocols and application issues to enable researchers and application developers to get up to speed quickly on how the different protocols fit together to deliver desired functionalities without having to go through RFCs and the standards specifications. We also provide an overview of some of the key IoT challenges presented in the recent literature and provide a summary of related research work. Moreover, we explore the relation between the IoT and other emerging technologies including big data analytics and cloud and fog computing. We also present the need for better horizontal integration among IoT services. Finally, we present detailed service use-cases to illustrate how the different protocols presented in the paper fit together to deliver desired IoT services.

6,131 citations

Proceedings ArticleDOI
01 Aug 1999
TL;DR: This paper believes that localized algorithms (in which simple local node behavior achieves a desired global objective) may be necessary for sensor network coordination.
Abstract: Networked sensors-those that coordinate amongst themselves to achieve a larger sensing task-will revolutionize information gathering and processing both in urban environments and in inhospitable terrain. The sheer numbers of these sensors and the expected dynamics in these environments present unique challenges in the design of unattended autonomous sensor networks. These challenges lead us to hypothesize that sensor network coordination applications may need to be structured differently from traditional network applications. In particular, we believe that localized algorithms (in which simple local node behavior achieves a desired global objective) may be necessary for sensor network coordination. In this paper, we describe localized algorithms, and then discuss directed diffusion, a simple communication model for describing localized algorithms.

3,044 citations

Journal ArticleDOI
01 May 2005
TL;DR: In this paper, several fundamental key aspects of underwater acoustic communications are investigated and a cross-layer approach to the integration of all communication functionalities is suggested.
Abstract: Underwater sensor nodes will find applications in oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance applications. Moreover, unmanned or autonomous underwater vehicles (UUVs, AUVs), equipped with sensors, will enable the exploration of natural undersea resources and gathering of scientific data in collaborative monitoring missions. Underwater acoustic networking is the enabling technology for these applications. Underwater networks consist of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over a given area. In this paper, several fundamental key aspects of underwater acoustic communications are investigated. Different architectures for two-dimensional and three-dimensional underwater sensor networks are discussed, and the characteristics of the underwater channel are detailed. The main challenges for the development of efficient networking solutions posed by the underwater environment are detailed and a cross-layer approach to the integration of all communication functionalities is suggested. Furthermore, open research issues are discussed and possible solution approaches are outlined. � 2005 Published by Elsevier B.V.

2,864 citations

Journal ArticleDOI
TL;DR: This article takes advantage of the inherent redundancy in ad hoc networks-multiple routes between nodes-to defend routing against denial-of-service attacks and uses replication and new cryptographic schemes to build a highly secure and highly available key management service, which terms the core of this security framework.
Abstract: Ad hoc networks are a new wireless networking paradigm for mobile hosts. Unlike traditional mobile wireless networks, ad hoc networks do not rely on any fixed infrastructure. Instead, hosts rely on each other to keep the network connected. Military tactical and other security-sensitive operations are still the main applications of ad hoc networks, although there is a trend to adopt ad hoc networks for commercial uses due to their unique properties. One main challenge in the design of these networks is their vulnerability to security attacks. In this article, we study the threats on ad hoc network faces and the security goals to be achieved. We identify the new challenges and opportunities posed by this new networking environment and explore new approaches to secure its communication. In particular, we take advantage of the inherent redundancy in ad hoc networks-multiple routes between nodes-to defend routing against denial-of-service attacks. We also use replication and new cryptographic schemes, such as threshold cryptography, to build a highly secure and highly available key management service, which terms the core of our security framework.

2,661 citations