Three architectures for trusted data dissemination in edge computing

Edge computing pushes application logic and the underlying data to the edge of the network, with the aim of improving availability and scalability. As the edge servers are not necessarily secure, there must be provisions for users to validate the results—that values in the result tuples are not tampered with, that no qualifying data are left out, that no spurious tuples are introduced, and that a query result is not actually the output from a different query. This paper aims to address the challenges of ensuring data integrity in edge computing. We study three schemes that enable users to check the correctness of query results produced by the edge servers. Two of the schemes are our original contributions, while the third is an adaptation of existing work. Our study shows that each scheme offers different security features, and imposes different demands on the edge servers, user machines, and interconnecting network. In other words, all three schemes are useful for different application requirements and resource configurations.     

Demand-driven caching in multiuser environment

We propose a novel demand-driven caching framework, called cache-on-demand (CoD). In CoD, intermediate/final answers of existing running queries are viewed as virtual caches that can be materialized if they are beneficial to incoming queries. Such an approach is essentially nonspeculative: the exact cost of investment and the return on investment are known, and the cache is certain to be reused! We address several issues for CoD to be realized. We also propose three optimizing strategies: Conform-CoD, Scramble-CoD, and Integrated-CoD. Conform-CoD and Scramble-CoD are based on a two-phase optimization framework, while Integrated-CoD operates in a single-phase framework. We conducted extensive performance study to evaluate the effectiveness of these algorithms. Our results show that all the CoD-based schemes can provide substantial performance improvement when compared with a predictive scheme and a no-caching scheme.