Abstract-The emergence of cloud environments has made feasible the delivery of Internet-scale services by addressing a number of challenges such as live migration, fault tolerance and quality of service. However, current approaches do not tackle key issues related to cloud storage, which are of increasing importance given the enormous amount of data being produced in today's rich digital environment (e.g. by smart phones, social networks, sensors, user generated content). In this paper we present the architecture of a scalable and flexible cloud environment addressing the challenge of providing data-intensive storage cloud services through raising the abstraction level of storage, enabling data mobility across providers, allowing computational and content-centric access to storage and deploying new data-oriented mechanisms for QoS and security guarantees. We also demonstrate the added value and effectiveness of the proposed architecture through two real-life application scenarios from the healthcare and media domains.

Cloud storage systems provide highly scalable and continuously available storage services to millions of geographically distributed clients. In order for users to trust their data to these systems, they need to be confident that their data is secure. Thus, cloud services should implement an access control mechanism preventing unauthorized access and manipulation of their data. This chapter presents the existing access control mechanisms and describes their advantages and limitations in the Cloud set-up. The authors address the main access control aspects that include managing the identities and defining access policies. Furthermore, they describe more complex scenarios of identity federation and integration of separate identity silos which is required in various scenarios, like collaboration, merge on acquisition, or migration. For each topic, the authors present the existing solutions and describe the motivation for the architecture developed by the VISION Cloud project.

Despite the huge economic, handling, and computational benefits of the cloud technology, the multitenant and geographically distributed nature of clouds hides a large crowd of security and regulatory issues to be addressed. The main reason for these problems is the unavoidable loss of physical control that costumers are forced to accept when opting for the cloud model. This aspect, united with the lack of knowledge (i.e. transparency) of the vendor’s infrastructure implementation, represents a nasty question when costumers are asked to respond to audit findings, produce support for forensic investigations, and, more generically, to ensure compliance with information security standards and regulations. Yet, support for security standards compliance is a need for cloud providers to overcome customers hesitancy and meet their expectations. In this context, tracking, auditing, and reporting practices, while transcending the compliance regimes, represent the primary vehicle of assurance for security managers and auditors on the achievement of security and regulatory compliance objectives. The aim of this chapter is to provide a roundup of crucial requirements resulting from common security certification standards and regulation. Then, the chapter reports an overview of approaches and methodologies for addressing compliance coming from the most relevant initiatives on cloud security and a survey of what storage cloud vendors declare to do in terms of compliance. Finally, the SIEM-based approach as a supporting technology for the achievement of security compliance objectives is described and, the architecture of the security compliance component of the VISION Cloud architecture is presented.