Cloud Computing is a technology with vast impact on IT systems. Costs can be significantly reduced through on-demand purchase of CPU time, memory and storage, offering high flexibility. The main reason to avoid cloud technology still is security. This leads to a lack of trust in cloud services. Most cloud providers secure their systems only against external adversaries by using firewalls and secure connections. Internal adversaries, however, remain a big threat in this scenario. Especially when using mobile devices as clients, usable security with a low performance impact remains a challenge. In this paper, we present concepts for using software as a service with mobile devices while guaranteeing a high level of data protection. MimoSecco uses an innovative encryption scheme and hard-to-clone secure hardware to guarantee data protection. Top secret data is encrypted directly, processible confidential data is encrypted and fragmented by the database proxy and transferred to different servers. Context-based access control makes the misuse of mobile devices for unauthorized data access difficult. These set of measures raises the privacy level of cloud computing significantly.