1. INTRODUCTION
Cloud computing delivers infrastructure, platform, and software that are made available as
subscription-based services in a pay-as-you-go model to consumers. These services are referred
to as Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service
(SaaS) in industries. The importance of these services was highlighted in a recent report from the
University of Berkeley as: ‘Cloud computing, the long-held dream of computing as a utility has