Privacy and security in cloud computing is an important concern for both the public and private sector. Cloud computing allows the use of internet-based services to support business process and rental of IT services on a utility-like basis. While cloud computing offers a massive concentration of resources, it poses risks for privacy preservation. The expected loss from a single breach can be significant and the heterogeneity of "Users" represents an opportunity of multiple and collaborative threats. Problems associated with trusted 3rd party managed cloud computing stem from loss of control, lack of trust (mechanisms) and multi-tenancy.