Security mechanisms for platform-as-a-service cloud

This doctoral study is aimed to design secure mechanisms for Platform-as-a-Service clouds. The thesis brings integrated solutions to the many aspects of the security problems of the Platform-as-a-Service clouds. The thesis starts with an attempt to fix the common security problems of concurrent Platform-as-a-Service clouds. Such clouds provide computational power by threads. Thread isolation is the main concern to not to interfere the data of the tenants. Thread isolation solutions are sought and its limits are shown. Then, the main proposition is made as utilization of processes instead of threads. A unified design integrating many security solutions is presented. Possible problems and solutions to these problems are enlisted. The design is enhanced with two novel mechanisms. The paradigm of secure execution and isolation of processes in the cloud as well as management of access control and governance of permissions to the cloud resources are integrated through cryptologic mechanisms. Also, a fair, secure logging mechanism is introduced. In this mechanism occurred events are neutrally and undeniably recorded to logs; as an alternative to problematic conventional logging mechanisms in which only one of the parties is controlling the records. As conclusion, a paradigm shift is proposed from concurrent thread-based Platform-as-a-Service clouds to process-based ones; as the benefits of the latter is emphasized throughout the thesis. "Security mechanisms for Platform-as-a-Service cloud" that are aimed to feasibly and conveniently solve all defined problems in an integrated manner are designed. The thesis is comprehensive in the subject of Platform-as-a-Service with its contributions to its security.