  By virtue of technology and benefit advantages, cloud computing has
increasingly attracted a large number of potential cloud consumers (PCC) plan
to migrate the traditional business to the cloud service. However, trust has
become one of the most challenging issues that prevent the PCC from adopting
cloud services, especially in trustworthy cloud service selection. Besides, due
to the diversity and dynamic of quality of service (QoS) in the cloud
environment, the existing trust assessment methods based on the single constant
value of QoS attribute and the subjective weight assignment are not good enough
to provide an effective solution for PCCs to identify and select a trustworthy
cloud service among a wide range of functionally-equivalent cloud service
providers (CSPs). To address the challenge, a novel assessment and selection
framework for trustworthy cloud service, FASTCloud, is proposed in this study.
This framework facilitates PCCs to select a trustworthy cloud service based on
their actual QoS requirements. In order to accurately and efficiently assess
the trust level of cloud services, a QoS-based trust assessment model is
proposed. This model represents a trust level assessment method based on the
interval multiple attributes with an objective weight assignment method based
on the deviation maximization to adaptively determine the trust level of
different cloud services provisioned by candidate CSPs. The advantage of the
proposed trust level assessment method in time complexity is demonstrated by
the performance analysis and comparison. The experimental result of a case
study with an open-source dataset shows that the trust model is efficient in
cloud service trust assessment and the FASTCloud can effectively help PCCs
select a trustworthy cloud service.
