Cost-effective and fault-tolerant identity-based key management for configurable hierarchical cloud environments

2017 ◽  
Vol 2017 (7) ◽  
pp. 16-20 ◽  
Author(s):  
Manreet Sohal ◽  
Sandeep Sharma
Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1330
Author(s):  
Jason Chia ◽  
Ji-Jian Chin ◽  
Sook-Chin Yip

The security of cryptographic schemes is proven secure by reducing an attacker which breaks the scheme to an algorithm that could be used to solve the underlying hard assumption (e.g., Discrete Logarithm, Decisional Diffie–Hellman). The reduction is considered tight if it results in approximately similar probability bounds to that of solving the underlying hard assumption. Tight security is desirable as it improves security guarantees and allows the use of shorter parameters without the risk of compromising security. In this work, we propose an identity-based identification (IBI) scheme with tight security based on a variant of the Schnorr signature scheme known as TNC signatures. The proposed IBI scheme enjoys shorter parameters and key sizes as compared to existing IBI schemes without increasing the number of operations required for its identification protocol. Our scheme is suitable to be used for lightweight authentication in resource-constrained Wireless Sensor Networks (WSNs) as it utilizes the lowest amount of bandwidth when compared to other state-of-the-art symmetric key lightweight authentication schemes. Although it is costlier than its symmetric key counterparts in terms of operational costs due to its asymmetric key nature, it enjoys other benefits such as decentralized authentication and scalable key management. As a proof of concept to substantiate our claims, we perform an implementation of our scheme to demonstrate its speed and memory usage when it runs on both high and low-end devices.


Author(s):  
Umakanta Mahanta ◽  
Bhabesh Chandra Mohanta ◽  
Anup Kumar Panda ◽  
Bibhu Prasad Panigrahi

Torque ripple reduction is one of the major challenges in switching table-based direct torque control (DTC) while operating for open phase faults of an induction motor, as the switching vectors are unevenly distributed. This can be minimized by increasing the level of the inverter and with the use of multi-phase motors. Fuzzy logic-based DTC is another solution to the above problem. In this paper, a comparative analysis is done between switching table-based DTC (ST-DTC) and fuzzy logic-based DTC for increasing the performance during open phase faults of a five-phase induction motor. The result shows that in fuzzy logic-based DTC with a two-level inverter, the torque ripple is reduced by 5.164% as compared with ST-DTC with a three-level inverter. The fuzzy logic-based DTC with the three-level inverter also gives better performance as compared with fuzzy logic-based DTC with the two-level inverter. The current ripple also reduced by 9.605% with respect to ST-DTC. Thus, fuzzy logic-based DTC is more suitable and cost effective for open phase fault-tolerant drives.


2021 ◽  
Vol 20 (5s) ◽  
pp. 1-22
Author(s):  
Haoran Li ◽  
Chenyang Lu ◽  
Christopher D. Gill

Fault-tolerant coordination services have been widely used in distributed applications in cloud environments. Recent years have witnessed the emergence of time-sensitive applications deployed in edge computing environments, which introduces both challenges and opportunities for coordination services. On one hand, coordination services must recover from failures in a timely manner. On the other hand, edge computing employs local networked platforms that can be exploited to achieve timely recovery. In this work, we first identify the limitations of the leader election and recovery protocols underlying Apache ZooKeeper, the prevailing open-source coordination service. To reduce recovery latency from leader failures, we then design RT-Zookeeper with a set of novel features including a fast-convergence election protocol, a quorum channel notification mechanism, and a distributed epoch persistence protocol. We have implemented RT-Zookeeper based on ZooKeeper version 3.5.8. Empirical evaluation shows that RT-ZooKeeper achieves 91% reduction in maximum recovery latency in comparison to ZooKeeper. Furthermore, a case study demonstrates that fast failure recovery in RT-ZooKeeper can benefit a common messaging service like Kafka in terms of message latency.


2018 ◽  
Vol 8 (3) ◽  
pp. 20-31 ◽  
Author(s):  
Sam Goundar ◽  
Akashdeep Bhardwaj

With mission critical web applications and resources being hosted on cloud environments, and cloud services growing fast, the need for having greater level of service assurance regarding fault tolerance for availability and reliability has increased. The high priority now is ensuring a fault tolerant environment that can keep the systems up and running. To minimize the impact of downtime or accessibility failure due to systems, network devices or hardware, the expectations are that such failures need to be anticipated and handled proactively in fast, intelligent way. This article discusses the fault tolerance system for cloud computing environments, analyzes whether this is effective for Cloud environments.


Author(s):  
Nidhal Mahmud

The use of robotics systems is increasingly widespread and spans a variety of application areas. From healthcare, to manufacturing, to space missions, these systems are typically conceived to perform dangerous or critical tasks. The nature of such tasks (e.g., surgery operations or radioactive waste clean-up) places high demands on the dependability of robotics systems. Fault tree analysis is among the most often used dependability assessment techniques in various domains of robotics. However, fault tree analysis of cost-effective fault tolerant robotics systems requires compositional synthesis of fault trees extended with the expressive power to allow analyzing the sequential dependencies among the components. Thereafter, a relevant experience from the automotive domain is presented. This consists mainly of a suitable synthesis approach that computes expressions of global failure conditions from the dysfunctional behavior local to the components. The benefits of the approach to dependability analysis of robotics architectures are highlighted by using a fault-tolerant example system.


Author(s):  
Nidhal Mahmud

The use of robotics systems is increasingly widespread and spans a variety of application areas. From healthcare to manufacturing to space missions, these systems are typically conceived to perform dangerous or critical tasks. The nature of such tasks (e.g., surgery operations or radioactive waste clean-up) places high demands on the dependability of robotics systems. Fault tree analysis is among the most often used dependability assessment techniques in various domains of robotics. However, fault tree analysis of cost-effective fault tolerant robotics systems requires compositional synthesis of fault trees extended with the expressive power to allow analyzing the sequential dependencies among the components. Thereafter, a relevant experience from the automotive domain is presented. This consists mainly of a suitable synthesis approach that computes expressions of global failure conditions from the dysfunctional behavior local to the components. The benefits of the approach to dependability analysis of robotics architectures are highlighted by using a fault-tolerant example system.


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