A Research Project Submitted In Partial Fulfillment Of The Requirements For The Award Of Degree Of Master Of Science Degree In Data Communication In The School Of Computing And Information Management At KCA University.Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g. networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. It can be deployed in four implementation architectural models; private cloud, public cloud, community cloud and a hybrid cloud. Its key characteristics are: Elasticity, Scalability of infrastructure, Broad network access, Location independence, Reliability, Economies of scale and cost effectiveness, Sustainability. The security and privacy of data hosted in a cloud environment is the concern of any organizations. There are internal or external threats to the cloud environment. The top three major security challenges identified by the Cloud Security Alliance in 2013 are: (i) data breaches, (ii) data loss and (iii) account or service traffic hijacking. The paper reviews the data privacy and security journals in a cloud environment and provides an enhanced model of addressing these common threats/concerns. After evaluating the different security models, the paper identified the three tier security model as proposed by Navia and Clara (2013), as the most effective model for cloud environments. Further scrutiny indicated that the model could be enhanced by incorporating additional security measures and procedures in the various sub components to make it more responsive to the security and privacy demands of modern day cloud environments. The details of the enhancements are presented in chapter 4 of this paper and an implementation to support the concept. The research findings are that enhancing the authentication of users the cloud environment can be secured.