ED-BeCT : An enhanced dynamic behavioral cloud trust model to evaluate the trustworthiness of the cloud service provider

Abstract

Cloud computing is an evolving technology providing the delivery of on-demand calculating services to offer scalable resources dynamically in an economical manner. The companies that provide these types of services enable users to store their data in, and exchange information with a virtual space remotely. However, this fact makes this technology prone to various risks and security threats. Thus, in cloud environments, assessing the trustworthiness is a momentous challenge that requires much effort and time to build up users’ confidence to choose a trustworthy cloud service provider. Trust has been studied by many researchers using several techniques and evaluating various trust characteristics. In fact, conceptually, trust has a vague notion and in cloud computing, involves diverse trust characteristics such as security, reliability, auditability, multi-tenancy and so on. Although extensive research has been carried out on trust in cloud environments, no single study exists which evaluates trust with standard measures from different perspectives. In view of these issues, our objective in this thesis is to propose a comprehensive cloud trust model based on existing system and software quality standards as well as to consider the cloud services behavior to be compared with the proposed service level agreements (SLAs) to filter qualified cloud service providers. In the context of a proposal for an Enhanced Dynamic Behavioral Cloud Trust (ED-BeCT) model, we study the applicable system and software quality standards to find standard trust characteristics. We analyze the literature to derive the commonly recognized trust characteristics applicable for evaluating trust in cloud computing. Additionally, we derive proper measures for each trust characteristic to increase the accuracy of the proposed model in trust assessment. Concerning the different aspects of cloud computing, we generalize these trust measures for the three types of cloud service models (i.e. Software as a Service, Platform as a Service, Infrastructure as a Service). To consider the level of importance of each trust characteristic, we apply full consistency method (FUCOM) to calculate appropriate weights. In this method, the weights are calculated based on the mathematical transitivity conditions and equal relations between the weights and the comparative priorities of the trust characteristics. The final value of the trust is determined by applying the calculated weights in the normalized values of the trust measures in the SAW (Simple Additive Weighting) method. Our work thereby introduces a cloud trust model to overcome the deficiencies of the prior models proposed by other researchers. Throughout this thesis, the presented detail and analysis of the model shows that the proposed model is accurate and has the appropriate capabilities to calculate trust in cloud computing and evaluate the provided cloud services.

Date	7 Oct 2020
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Witold Suryn (Supervisor)