Solving Security and Availability Challenges in Public Clouds

Cloud Computing as a service-on-demand architecture has grown in importance over the previous few years. One driver of its growth is the ever-increasing amount of data that is supposed to outpace the growth of storage capacity. The usage of cloud technology enables organizations to manage their data with low operational expenses. However, the benefits of cloud computing come along with challenges and open issues such as security, reliability, and the risk to become dependent on a provider for its service. In general, a switch of a storage provider is associated with high costs of adapting new APIs and additional charges for inbound and outbound bandwidth and requests. In this chapter, the authors present a system that improves availability, confidentiality, and reliability of data stored in the cloud. To achieve this objective, the authors encrypt users’ data and make use of the RAID-technology principle to manage data distribution across cloud storage providers. Further, they discuss the security functionality and present a proof-of-concept experiment for the application to evaluate the performance and cost effectiveness of the approach. The authors deploy the application using eight commercial cloud storage repositories in different countries. The approach allows users to avoid vendor lock-in and reduces significantly the cost of switching providers. They also observe that the implementation improved the perceived availability and, in most cases, the overall performance when compared with individual cloud providers. Moreover, the authors estimate the monetary costs to be competitive to the cost of using a single cloud provider.