Cloud CPU Verification Scheme for Individual End Users

In this paper, a user-based CPU verification scheme is proposed for the cloud cheating detection problem, where the cloud service provider offers insufficient CPU resources that are bought by the user. In this scheme, a predefined computational task is constructed for the cloud to execute. Then, we compare the difference of the actual execution time (recorded by the user) and the theoretical execution time, as to determine whether the cloud is cheating or not. A time-lock puzzle is introduced to construct the predefined computational task, so that this task is guaranteed to be fully executed by the cloud. Our cheating detection process has a higher probability of detecting cloud cheating if using a larger predefined computational task, which in turn costs more time. Further analysis shows that, if the total detection time is limited, it is better to detect cloud cheating using small-scale and short-length cheating detecting processes multiple times, as opposed to large-scale and long-length processes a few times. We also discuss the heterogeneity of CPU resources through two simple models. Finally, the feasibility and validity of our scheme is shown in the real system evaluations.