Distributed data possession checking for securing multiple replicas in geographically-dispersed clouds

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摘要

Distributing multiple replicas in geographically-dispersed clouds is a popular approach to reduce latency to users. It is important to ensure that each replica should have availability and data integrity features; that is, the same as the original data without any corruption and tampering. Remote data possession checking is a valid method to verify the replicasʼs availability and integrity. Since remotely checking the entire data is time-consuming due to both the large data volume and the limited bandwidth, efficient data-possession-verifying methods generally sample and check a small hash (or random blocks) of the data to greatly reduce the I/O cost. Most recent research on data possession checking considers only single replica. However, multiple replicas data possession checking is much more challenging, since it is difficult to optimize the remote communication cost among multiple geographically-dispersed clouds. In this paper, we provide a novel efficient Distributed Multiple Replicas Data Possession Checking (DMRDPC) scheme to tackle new challenges. Our goal is to improve efficiency by finding an optimal spanning tree to define the partial order of scheduling multiple replicas data possession checking. But since the bandwidths have geographical diversity on the different replica links and the bandwidths between two replicas are asymmetric, we must resolve the problem of Finding an Optimal Spanning Tree in a Complete Bidirectional Directed Graph, which we call the FOSTCBDG problem. Particularly, we provide theories for resolving the FOSTCBDG problem through counting all the available paths that viruses attack in clouds network environment. Also, we help the cloud users to achieve efficient multiple replicas data possession checking by an approximate algorithm for tackling the FOSTCBDG problem, and the effectiveness is demonstrated by an experimental study.

论文关键词:Cloud computing,Multiple replicas data possession checking,Data security,Optimal spanning tree,Complete bidirectional directed graph

论文评审过程:Received 25 August 2010, Revised 20 May 2011, Accepted 8 December 2011, Available online 29 December 2011.

论文官网地址:https://doi.org/10.1016/j.jcss.2011.12.018