Trust and reputation systems in cloud data centers: a variational approach

The aim of this paper is to introduce a novel equilibrium model based on trust and reputation systems to study cloud data centers, physical or virtual facilities that host and manage cloud computing resources to support the delivery of online services, applications, storage, and other IT resources. In our model, the physical hardware of the center, such as servers, evaluate each other with the objective of maximizing their utility (gain minus costs), expressed in terms of reputation. The reputation of each server is defined as a weighted sum of the trust values it receives, where weights are assigned based on the distance between servers. A variational approach is applied to determine an equilibrium configuration of the system from the user’s perspective. The equilibrium solution is analyzed with respect to its existence and uniqueness. Furthermore, numerical simulations are conducted to test and validate the model. Finally, a sensitivity analysis on the initial reputation of the servers and the distance parameter is performed.