Abstract:

The operation of bring-your-own-device (BYOD) in the cloud has not only opened cloud servers to more threats but inflicted additional costs on cloud security as it would have to monitor employee devices and their operations. Many organizations therefore have adopted zero trust scheme for BYOD access control management in cloud environment. However, zero trust model introduces extra cost and hostility against internal employees, who have a certain level of trust, as against outsiders. This paper posits that trust quantification for BYOD access control management should be determined by cloud service providers and employers in a dynamic and continuous manner based on session and information values. The paper therefore presents a collaborative-based dynamic trust model that fuses the perspectives of BYOD employer and cloud service provider agents (trustees) for BYOD Nodes (trustors) access control management. The trustees provide prior evidences about the BYOD requests from which plausible inferences are drawn. Three framing of trusts including employee, device and program trusts are formulated based on reliable trust metrics. Dempster-Shafer Belief Function is used to evaluate the belief scores of the trustors’ requests from the probabilities assigned by the trustees. The model is applied to two BYOD nodes, with varying session and information values. The outcomes reveal that the collaborative-based dynamic trust model ensures reduced cost and improved usability compared to zero trust model.