  Cloud computing has been attracting the attention of several researchers both
in the academia and the industry as it provides many opportunities for
organizations by offering a range of computing services. For cloud computing to
become widely adopted by both the enterprises and individuals, several issues
have to be solved. A key issue that needs special attention is security of
clouds, and trust management is an important component of cloud security. In
this paper, the authors look at what trust is and how trust has been applied in
distributed computing. Trust models proposed for various distributed system has
then been summarized. The trust management systems proposed for cloud computing
have been investigated with special emphasis on their capability, applicability
in practical heterogonous cloud environment and implementabilty. Finally, the
proposed models/systems have been compared with each other based on a selected
set of cloud computing parameters in a table.
