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A Novel Verification Scheme for Fine-Grained Top-k Queries in Two-Tiered Sensor NetworksMa, X., Song, H., Wang, J., Gao, J., Min, Geyong January 2014 (has links)
No / A two-tiered architecture with resource-rich master nodes at the upper tier and resource-poor sensor nodes at the lower tier is expected to be adopted in large scale sensor networks. In a hostile environment, adversaries are more motivated to compromise the master nodes to break the authenticity and completeness of query results, whereas it is lack of light and secure query processing protocol in tiered sensor networks at present. In this paper, we study the problem of verifiable fine-grained top- queries in two-tiered sensor networks, and propose a novel verification scheme, which is named Verification Scheme for Fine-grained Top- Queries (VSFTQ). To make top- query results verifiable, VSFTQ establishes relationships among data items of each sensor node using their orders, which are encrypted together with the scores of the data items and the interested time epoch number using distinct symmetric keys kept by each sensor node and the network owner. Both theoretical analysis and simulation results show that VSFTQ can not only ensure high probability of detecting forged and/or incomplete query results, but also significantly decrease the amount of verification information when compared with existing schemes.
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Ensuring Network Designs Meet Performance Requirements under FailuresYiyang Chang (6872636) 13 August 2019 (has links)
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<p>With the prevalence of web and cloud-based services, there is an ever growing
requirement on the underlying network infrastructure to ensure that business critical traffic is continually serviced with acceptable performance. Networks must meet
their performance requirements under failures. The global scale of cloud provider
networks and the rapid evolution of these networks imply that failures are the norm
in production networks today. Unplanned downtime can cost billions of dollars, and
cause catastrophic consequences. The thesis is motivated by these challenges and
aims to provide a principled solution to certifying network performance under failures. Network performance certification is complicated, due to both the variety of
ways a network can fail, and the rich ways a network can respond to failures. The
key contributions of this thesis are: (i) a general framework for robustly certifying
the worst-case performance of a network across a given set of uncertain scenarios. A
key novelty is that the framework models flexible network response enabled by recent
emerging trends such as Software-Defined Networking; (ii) a toolkit which automates
the key steps needed in robust certification making it suitable for use by a network
architect, and which enables experimentation on a wide range of robust certification
of practical interest; (iii) Slice, a general framework which efficiently classifies failure
scenarios based on whether network performance is acceptable for those scenarios,
and which allows reasoning about performance requirements that must be met over
a given percentage of scenarios. We also show applications of our frameworks in synthesizing designs that are guaranteed to meet a performance goal over all or a desired percentage of a given set of scenarios. The thesis focuses on wide-area networks, but
the approaches apply to data-center networks as well.</p></div></div></div>
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