1,721,050 research outputs found
Securing Communication in 6LoWPAN with Compressed IPsec
Full text linkReal-world deployments of wireless sensor networks (WSNs) require secure communication. It is important that a receiver is able to verify that sensor data was generated by trusted nodes. It may also be necessary to encrypt sensor data in transit. Recently, WSNs and traditional IP networks are more tightly integrated using IPv6 and 6LoWPAN. Available IPv6 protocol stacks can use IPsec to secure data exchange. Thus, it is desirable to extend 6LoWPAN such that IPsec communication with IPv6 nodes is possible. It is beneficial to use IPsec because the existing end-points on the Internet do not need to be modified to communicate securely with the WSN. Moreover, using IPsec, true end-to-end security is implemented and the need for a trustworthy gateway is removed. In this paper we provide End-to-End (E2E) secure communication between IP enabled sensor networks and the traditional Internet. This is the first compressed lightweight design, implementation, and evaluation of 6LoWPAN extension for IPsec. Our extension supports both IPsec’s Authentication Header (AH) and Encapsulation Security Payload (ESP). Thus, communication endpoints are able to authenticate, encrypt and check the integrity of messages using standardized and established IPv6 mechanisms
DHB-KEY - A Diffie-Hellman Key Distribution Protocol for Wireless Sensor Networks
Full text linkMany sensor network applications require secure communication between sensor nodes and the sink. This paper presents a key distribution scheme based on the well known Elliptic Curve Diffie-Hellman key exchange mechanism. The DHB-KEY scheme is performed in two stages. The first stage is carried out in a secure environment before network deployment. The second stage is carried out periodically using a single broadcast message. Each node arrives at a unique key it shares with the sink. This paper presents a first evaluation and a prototype implementation of the protocol. We have found that the presented key distribution approach uses energy and communication resources efficiently and has a low deployment complexity
Validating the Sensor Network Calculus by Simulations
Full text linkAbstract Network Calculus has been proposed and customized as a framework for worst-case analysis in wireless sensor networks (WSNs). It has been demonstrated that this so-called Sensor Network Calculus (SNC) is an effective network dimensioning tool as it allows us to calculate maximum message transfer delays and communication related energy consumption patterns before network deployment. So far it is unclear how the SNC calculated worst-case delay bounds compare to values experienced in real deployments. Our experiments presented in this paper show that an SNC worst-case delay prediction can be as little as 2.7% above the measured worst-case delay in a typical application scenario. Thus, it can be concluded that the SNC has a very practical relevance for dimensioning wireless sensor networks
A survey of requirements and standardization efforts for IP-telephony-security
Full text linkSecurity as a dimension of trustworthiness in IP-Telephony systems and protocols is a main condition for the commercial success of IP-Telephony. In this work, we present a survey of security requirements and show how various standardization efforts address these requirements. We describe the basic tasks and elements of IP-Telephony systems and compare them to Telephony via PSTNs to derive some possible attacks for example. We classify the security preconditions to achieve trustworthiness of users and providers in this systems. We list weighty criteria for further evaluation of security mechanisms which can fulfil these requirements. After this, we describe the integration of security mechanisms in current IP-Telephony protocols and figure out work areas which have to be solved in future
Vulnerabilities and security limitations of current IP telephony systems
Full text linkWithin the traditional telephone system a certain level of quality and security has been established over the years. If we try to use IP Telephony systems as a core part of our future communication infrastructure (e.g. as classical PBX enhancement or replacement) continuous high availability, stable and error-free operation and the protection of the privacy of the spoken word are challenges, that definitely have to be met. Since manufacturers start deploying new end systems and infrastructure components rather fast now - a critical inspection of their security features and vulnerabilities is mandatory. The critical presentation of the theoretical background of certain vulnerabilities, testing and attacking tools and the evaluation results reveals, that well-known security flaws become part of implementations in the new application area again and the security level of a number of examined solutions is rather insufficient
An Experimental Comparison of Event Driven and Multi-Threaded Sensor Node Operating Systems
Full text linkTwo different operating system types are currently considered for sensor networks: event driven and multi-threaded. This paper compares the two well-known operating systems TinyOS (event driven) and MANTIS (multi-threaded) regarding their memory usage, power consumption and processing capabilities. TinyOS and MANTIS are both ported to the DSYS25 sensor platform. Both operating systems are used to execute the same sensor network application and the aforementioned parameters of interest are measured. The results presented in this paper show for which set of applications each operating system is preferable
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
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