Cloud computing ecosystem is one of the trends currently being discussed in the domain of information technology and computing. Computing ecosystem allows smart usage of technology which means unneeded resources are saved such as power, computing resources, spaces for datacenters as well as saving huge amount of CO2 and electric circuit boards and machines. Cloud federation and its underlying techniques, is considered role model in sharing and expanding cloud business to provide better and cheaper services for end-users. In this thesis, we will survey and compare existing Identity Access Management ...