Fuzzy Rule-Based Expert System for Determining Trustworthiness of Cloud Service Providers

Cloud Computing has a great potential to transform the way we use technology. People have started using cloud services but they still have a lot of apprehensions resulting from the lack of trust on Cloud Service Provider (CSP) and the associated security risks. In this paper, we have proposed a fuzzy rule-based expert system that evaluates trustworthiness of a CSP from the viewpoint of consumers (called Direct-Trust), their Public-Review, and the Cloud Auditor (called Auditor-Trust). A survey has been conducted to rate the five CSPs on the basis of their Reliability, Performance, Security, and Usability. The data collected from the survey serve as the dataset to calculate the Direct-Trust and Public-Review. Auditor-Trust has been calculated using the data generated by Nasuni, a cloud storage company which evaluates CSPs on the basis of their Performance, Availability, Scalability, and Accuracy. Final Trustworthiness is then calculated by combining Direct-Trust, Public-Review, and Auditor-Trust. All the simulations have been done using Fuzzy Logic Toolbox of MATLAB. The results generated rank the CSPs according to their Final Trustworthiness. A scale of 1–5 has been used in all the calculations for ratings.