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Security in Wireless Sensor Networks
Published in Shafiullah Khan, Al-Sakib Khan Pathan, Nabil Ali Alrajeh, Wireless Sensor Networks, 2016
In policy-based defense mechanisms, decisions on access control and authentication techniques are made on the basis of a specified set of privacy policies. Molnar et al. have presented the concept of private authentication and demonstrated its application in the radio frequency (RF) identification (RFID) domain [130]. Duri et al. propose a policy-based framework for protecting sensor information, in which a computer inside a car acts as a trusted agent for location privacy [131]. Snekkenes introduces various parameters for access control that enable specifying policies in the context of a mobile network [132]. Some of the parameters are time of request, location, speed, and identity of the located object. Myles et al. describe the architecture of a centralized location server that controls access requests from client applications through a set of validator modules based on a set of XML-coded privacy policies [133]. Hengartner et al. discuss various challenges that arise in the specification and implementation of policies that control access to location information [134]. The authors also present a design framework of an access control mechanism in their study.
Wireless Sensor Network Security: A Survey
Published in Yang Xiao, Security in Distributed, Grid, Mobile, and Pervasive Computing, 2007
John Paul Walters, Zhengqiang Liang, Weisong Shi, Vipin Chaudhary
Policy-based approaches are currently a hot approach to address the privacy problem. The access control decisions and authentication are made based on the specifications of the privacy policies. In [57], Molnar and Wagner present the concept of private authentication, and give a general scheme for building private authentication with work logarithmic in the number of tags in (but not limited by) RFID (radio frequency identification) applications. In the automotive telematics domain, Duri and colleagues [20] propose a policy-based framework for protecting sensor information, where an in-car computer can act as a trusted agent. Snekkenes [77] presents advanced concepts for specifying policies in the context of a mobile phone network. These concepts enable access control based on criteria such as time of the request, location, speed, and identity of the located object. Myles and colleagues [58] describe an architecture for a centralized location server that controls access from client applications through a set of validator modules that check XML-encoded application privacy policies. Hengartner and Steenkiste [31] point out that access control decisions can be governed by either room or user policies. The room policy specifies who is permitted to find out about the people currently in a room, while the user policy states who is allowed to get location information about another user.
Application of Blockchain for Energy Transition Systems
Published in Muhammad Asif, Handbook of Energy Transitions, 2023
Gijs van Leeuwen, Tarek Alskaif, Bedir Tekinerdogan
The PoS algorithm was developed to counter some of the disadvantages of the PoW algorithm [17] Instead of relying on brute-force computational work, the PoS algorithm randomly selects a group of nodes to validate the network, which can be used on public and private networks. This is a lottery-type approach, where the chance of being selected increases with the amount of stake in the network—e.g., the amount of cryptocurrency held by a node. This greatly increases transaction speed and reduces energy consumption than PoW [19] A downside is lower security compared to PoW, as attackers would have to control a majority of the total resources within the network rather than computational power. Since computational power requires hardware and software resources, PoS is considered less secure. Another commonly used set of consensus mechanisms is BFT algorithms, which are voting-based algorithms [17] A verified and trustworthy set of validator nodes vote on the validity of transactions, and when enough votes are collected, the data is considered final. This makes BFT best suited to private networks where these validator nodes are known. The instant and straightforward finality provided by the BFT algorithm is a major advantage, while it suffers from relatively worse scalability, speed, and security. Finally, PoA is an algorithm similar to PoS in that validator nodes are randomly selected. Instead of selecting based on the size of their stake in the network, however, the PoA algorithm selects nodes based on the known validity of their identity or authority. This makes PoA-type algorithms especially suited for closed environments where privacy is a lower priority.
Development of machine tool communication method and its edge middleware for cyber-physical manufacturing systems
Published in International Journal of Computer Integrated Manufacturing, 2023
S M Nahian Al Sunny, Xiaoqing “Frank” Liu, Md Rakib Shahriar
MTComm operate service enables performing machine tool operations over the Internet. A client application initiates operate service by sending an MTCommOperations message via HTTP POST method to the machine’s agent. This XML message contains details of requested operation(s) and associated parameters, if any. Then the agent checks its validity using the aforementioned verification process. This step is very crucial as it prevents the machine from performing potentially harmful operations and damaging itself. It is a two-step process – the agent’s validator module first checks if the XML message is in proper format and then it uses the probe service to acquire all permitted operations and their parameters and verifies the incoming operational instructions with them. A parameter element may include constraints defining limitations and range of accepted values. If the requested operation or any of the parameters does not match with probe information, the request is rejected. For example, if a machine’s X axis can move to a maximum position of 200 mm and its current position is 120 mm, an operate request for moving the X axis 100 mm more will be rejected. Once the request is validated, the agent parses the message, creates an instruction dictionary, and forwards it to the adapter. The adapter than initiates and completes the operation by sending appropriate commands to the machine tool. Figure 4 illustrates the operate service process in a sequence diagram.