Trust Based Security for Cloud Systems
Even though Security, Privacy and Trust issues exists since the evolution of Internet, the reason why they are widely spoken these days is because of the Cloud Computing scenario. Any client/small organization/enterprise that processes data in the cloud is subjected to an inherent level of risk because outsourced services bypass the "Physical, logical and personnel controls" of the user. When storing data on cloud, one might want to make sure if the data is correctly stored and can be retrieved later. As the amount of data stored by the cloud for a client can be enormous, it is impractical (and might also be very costly) to retrieve all the data, if one's purpose is just to make sure that it is stored correctly.