The popularity of the Cloud rises, but there is still much insecurity in the IT-Security of a cloud solution. Companies want to be able to check, if the processes in the cloud are secure and trustworthy. This is possible with an external auditing system, which compares measured data with predefined rules. But there is a chance, that the measured data are manipulated on its way to the auditing system, before leaving the cloud. To prevent these threads, the measured data must be protected right after it is generated. This is possible with the forward integrity method, which builds a chain-of-trust for the measured data without need of a TPM.