Design & Development of a Computational Model using Virtualization and Multi-tenancy Technologies for Cloud Computing Architecture

Cloud computing has arrived as a solution to reduce costs in organizations and at the same time offer on-demand resources and computation without requiring to create an IT infrastructure. Services, such as Amazon Web Services (AWS) or Microsoft Azure provide a means for organizations to instantly provision and de-provision virtual machines (VM) depending on their needs, just paying for what they use. In order to make the necessary environment, cloud service providers (CSP) make use of virtualization technologies to maximize the value of their systems. Servers have always needed to run alone in physical machines to avoid other services to interfere with them; but the downside of this was the waste of resources. Virtualization enables the use of all the resources in a physical host by sharing them between the guest operating systems (OS). Many organizations have already deployed private clouds on their own infrastructures or through third parties. However, Public Clouds provide an additional advantage that makes it extremely attractive, cost savings. The resources for a cloud consumer seem to be unlimited by sharing all the host machines between different organizations. At the same time, the CSPs can easily maximize the use of each physical machine. Multi-tenancy is the name that receives this computational model. However, there is a drawback on multi-tenancy and public clouds. Host systems are shared between multiple tenants with different owners and one of them could potentially be a malicious attacker or even a competitor. Now someone trying to compromise an organization’s business processes or data will not need to break through their traditional lines of defense. The traditional perimeter in their networks no longer exists. Now an organization’s systems coexist shoulder to shoulder with unknown tenants with potential malicious intentions. The virtualization layer adds a new attack surface to be compromised where the hypervisor and the resident VMs can be the target. The alarms have been triggered, stopping many organizations on their path to the Cloud. This research paper aims to provide an overview of the security issues that this new computational model arises. The problem will be aboard from the general cloud computing term, through multi-tenancy, down to virtualization. The main goal is to explore and analyze the different threats that virtualization and multi-tenancy combined bring to the Cloud. More specifically, the venues to compromise a VM or a hypervisor in a physical machine will be analyzed and recommendations will be given on how to mitigate the risks.