The development of cloud computing services is speeding up the rate in which the organizations outsource their computational services or sell their idle computational resources. Even though migrating to the cloud remains a tempting trend from a financial perspective, there are several other aspects that must be taken into account by companies before they decide to do so. One of the most important aspects refers to security: amongst these security and trust issues, the user’s data has to be released to the cloud and thus leaves the protection sphere of the data owner.