Introduction

Introduction Cloud computing can be compared to early proliferation of electricity, where homes, businesses and towns find it difficult to produce or rely on their source of power. Hence, they connect to a greater power grid usually supported by power utilities. With this type of utility connection, there has been tremendous reduction in both time and cost, and greater access to and more availability of power (Eva, 2010). The National Institute of Standard and Technology (NIST) defined cloud computing as a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction (Micheal, 2010). With cloud computing, consumers and businesses use applications without installation and can access their personal files at any computer with Internet access (Lohr, 2007). This innovation represents a significant opportunity for service providers and enterprises (Eva, 2010). The same way homes and businesses rely on power grid, cloud computing has helped enterprise to save cost, increase flexibility and choice for computing resources through on-premise infrastructure (Eva, 2010). * Lecturer, Computer Science Department, Federal University Wukari, Taraba State, Nigeria. E-mail: nonnyraymond@yahoo.co.uk **Lecturer, Computer Science Department, Federal University Wukari, Taraba State, Nigeria; and is the corresponding author. E-mail: visittim@yahoo.com H©y b2r0i1d5 M IUodP.e lA flol rR Digahttas SReecsuerrivteyd i.n Cloud 7 There is no doubt today that cloud computing is one of the most enticing technologies due to its cost-efficiency and flexibility. Richard et al. (2009) reported that about fourteen (14) largest software companies (by market capitalization today) operate almost entirely on cloud. Paradigm shift to cloud computing has affected some subcategories in computer industry. A few among them are Internet Service Providers (ISPs), hardware manufacturers and to a greater extent, software companies (Harte- Hanks, 2011). While it will be difficult to predict how Internet companies will be affected, it is relatively easy to see how the main software and hardware companies are affected by this shift (Harte-Hanks, 2011). However, with this technology came security challenges too. Though cloud service providers trumpet the robustness and reliability of their systems, most of the times they claim that security in the cloud is tighter than in most enterprises (David, 2007). But the simple fact is that every security system that has ever been breached was once thought infallible. In this paper, security challenges as it concern computer and network intrusion or attacks that will be made possible or at least easier by using cloud and the legal implications of data and applications being held at the cloud are analyzed. This paper analyzes the delivery model of cloud computing laying emphasis on the three prominent service delivery models; Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS). It also looked at the security challenges that cloud computing offers service providers and enterprises hoping to leverage this new technology so as to improve their bottom line in this severe economic climate.