Cloud computing represents a major shift in the way we develop and deploy systems and services. It has many benefits such as better utilization of hardware resources by the ease of deployment, scalability, reduced costs, increased efficiency, and high availability of services using Internet. However, the security challenges related to cloud computing act as barrier to its widespread adoption. Cloud computing paradigm is also changing the traditional view of security introducing new service security risks and threats, and requires re-thinking of current assurance, development, testing, and verification methodologies. In particular, security assurance in the cloud is becoming a pressing need to increase the confidence of the cloud actors that the cloud and its services are behaving as expected, and requires novel approaches addressing SOA and cloud peculiarities. The third edition of IWSAC workshop aims to address the security assurance issues related to the deployment of services in the Cloud, along with evaluating their impact on traditional security solutions for software and network systems.