Multiple-clouds computing security approaches: a comparative study

Relying on a single cloud as a storage service is not a proper solution for a number of reasons; for instance, the data could be captured while being uploaded to the cloud, and the data could be stolen from the cloud using a stolen ID. There are a number of approaches that have been developed in order to provide a secure data storage relying on the multiple-cloud paradigms. Through this paper we will study, and evaluate the existing approaches that have been proposed as a solution for multiple cloud storage systems in terms of security, privacy, and integrity. In addition, we will provide a brief overview of the concept of information dispersal strategies and provide an overview of state-of-the-art multiple cloud storage approaches. After that, all these approaches will be analysed with respect to pre-defined criteria/properties. Finally, we identify and highlight the obstacles/limitation in terms of usability, operational cost, and the lack of security, privacy, integrity, and access features for these approaches, which are very critical direction for future research on multiple cloud storage.