Cloud Computing Security is an important theme connected to international privacy laws such as the European GDPR. Companies are required to secure their systems and encrypt sensible personal data to an appropriate level. This leads to different security measures and security solutions in different companies and industries. The purpose of the study was to identify suitable security measures and data encryptions in different company settings and their connection to Cloud Computing environments. A literature review and a multiple case study in four different companies from different industries were conducted. The findings were then analysed in a cross-case analysis split into the focus areas of Cloud Computing, Security issues and measures and different encryption methods. Based on these results, a model was developed combining both the findings from the review and the case-study, emphasizing the importance of appropriate security measures implemented in the Cloud Computing environment for both clients and service providers as well as the importance of the underlying trust requirements to enable a successful joint-venture. The final discussion addresses theoretical, ethical and managerial implications as well as the limitations. Finally, an outlook on future research topics in the field of Cloud Computing, IT Security and Encryption Methods is given and discussed.