School of Computing Science

PhD Theses

The Role of Transparency and Trust in the Selection of Cloud Service Providers (2015)

The full text of this thesis is available from the Newcastle University Library website: https://theses.ncl.ac.uk/dspace/handle/10443/3025

Almanea, M.I.M., School of Computing Science, University of Newcastle upon Tyne

Potential customers started to adopt cloud computing because of the promised benefits such as the flexibility of resources and most importantly cost reduction. In spite of the benefits that could flow from its adoption, cloud computing brings new challenges associated with its potential lack of transparency, trust and loss of controls. In the shadow of these challenges, the number of cloud service providers in the marketplace is growing, making the comparison and selection process very difficult for potential customers and requiring methods for selecting trustworthy and transparent providers. This thesis discusses the existing tools, methods and frameworks that promote the adoption of cloud computing models, and the selection of trustworthy cloud service providers. A set of customer assurance requirements has been proposed as a basis for comparative evaluation, and is applied to several popular tools (Cloud Security Alliance Security, Trust, and Assurance Registry (CSA STAR), CloudTrust Protocol (CTP), Complete, Auditable, and Reportable Approach (C.A.RE) and Cloud Provider Transparency Scorecard (CPTS)). In addition, a questionnaire-based survey has been developed and launched where by respondents evaluate the extent to which these tools have been used, and assess their usefulness. The majority of respondents agreed on the importance of using the tools to assist migration to the cloud and, although most respondents have not used the tools, those who have used them reported them to be helpful. It has been noticed that there might be a relationship between a tool's compliance to the proposed requirements and the popularity of using these tools, and these results should encourage cloud providers to address customers' assurance requirements. Some previous studies have focused on comparing cloud providers based on trustworthiness measurement and others focused only on transparency measurement. In this thesis, a framework (called CloudAdvisor) is proposed that couples both of these features. CloudAdvisor aims to provide potential cloud customers with a way to assess trustworthiness based on the history of the cloud provider and to measure transparency based on the Cloud Controls Matrix (CCM) framework. The reason for choosing CCM is because it aims to promote transparency in cloud computing by adopting the best industry standards. The selection process is based on a set of assurance requirements that, if met by the cloud provider or if it has been considered in a tool, could bring assurance and confidence to cloud customers. Two possible approaches (Questionnaire-based and Simulation-based approach) are proposed in order to evaluate the CloudAdvisor framework.