Cloud computing is an emerging technology in IT world. It is a set of IT services such as software's, applications and hardware resources that are provided to a customer over a network on a leased basis and with the ability to scale up or down their service requirements. Usually cloud computing services are delivered by a third party provider who owns the infrastructure.
To mention few advantages it includes scalability, resilience, flexibility, efficiency and outsourcing non-core activities. Cloud Computing initiatives could affect the enterprises within two to three years as it has the potential to significantly change IT. The major issue and the most of the research are carried on the security issues which hampers the growth of cloud. This paper provides a survey of the security challenges focusing on the cloud computing types and the service delivery types.