In cloud environment, many functionally similar cloud services are available. But, the services differ in Quality of Service (QoS) levels, offered by them. There is a diversity in user requirements about the expected qualities of cloud services. Trust is a measure to understand whether a cloud service can adequately meet the user requirements. Consequently, trust assessment plays a significant role in selecting the suitable cloud service. This paper proposes preferences based customized trust model (PBCTM) for trust assessment of cloud services. PBCTM takes into account user requirements about the expected quality of services in the form of preferences. Accordingly, it performs customized trust assessment based on the evidences of various attributes of cloud service. PBCTM enables elastic trust computation, which is responsive to dynamically changing user preferences with time. The model facilitates dynamic trust based periodic selection of cloud services according to varying user preferences. Experimental results demonstrate that the proposed preferences based customized trust model outperforms the other model in respect of accuracy and degree of satisfaction.Copyright c 2018 Institute of Advanced Engineering and Science.All rights reserved.Corresponding Author: Shilpa Deshpande, Department of Computer Engineering, College of Engineering Pune, Savitribai Phule Pune University, Pune, Maharashtra, India Email: shilpshree@yahoo.com
INTRODUCTIONCloud computing has entered mainstream and received wider acceptance. It is increasingly adopted by individuals, small and medium scale enterprises (SMEs) and government organizations to run their critical applications. The reason for this acceptance is the characteristics of cloud like scalability, on demand service, anytime-anywhere access, economic benefits of pay-per-use, delegation of maintenance and administration, performance and disaster recovery. Cloud services have proliferated to include software as a service, database as a service, platform as a service, infrastructure as a service, security as a service and storage as a service [1]. Cloud environment still remains challenging to rely on because of factors like loss of control over applications and data, increased threats of security [2], performance issues related to virtualization [3], enterprise grade availability requirements [4,5,6] and adequately meeting Quality of Service (QoS) expectations of users [7].Cloud computing has compelling advantages yet challenges too. For an enterprise to adopt cloud, it is important that enterprise has a certain belief that advantages of cloud can be realized. Trust is a measure of this belief [8]. Conventionally, people rely on reputation [4,8], service level agreement (SLA) [6,9], self-assessment [8,9] and cloud auditing [8,9] for trust assessment in cloud environment. However, trust assessment in cloud environment poses further important issues, which are revealed as part of the following discussion.Reputation based traditional trust assessment technique relies on ...