Cloud computing services consumers do not have enough reliable information about critical characteristics of their providers, such as performance, security, trust and privacy, compliance with laws and regulations, among others. Our proposal addresses these problems presenting a trust assessment framework that integrates three domains: Governance, Transparency, and Security Information. Our approach is consumer-centric and deals with trust aspects from the end-user's perspective. We use Indicators to communicate the outcomes, which aim to represent the expression of cybersecurity, manageability, and transparency of services under assessment. This paper includes an implementation proposal, prototype, and proof of concept, in which the framework was applied in a real scenario and executed over a long-term (18 months) usage simulation to verify its applicability, sensitivity, and robustness. Our study is intended for use by consumers of cloud computing who seek to know and measure levels of cybersecurity, protection of privacy, transparency of security, and high levels of quality in their services and infrastructure.

Information Security is an aggregation of people effort, processes and technology to help organizations at providing confidentiality, integrity and availability in their information assets. Nowadays, almost all technology services are heavily dependent on cloud computing under their various forms of service models. We realize there are weaknesses in cloud services concerning issues of performance, reliability, security, and privacy, among other issues. Cloud services consumers do not have enough information on these issues neither on compliance with laws and regulations. In this paper, we present a comprehensive mapping of works that deal with cloud trust aspects from user perspective. We aim at identifying how users or consumers of Cloud services measure trust on cloud computing services. Our main contributions are: (i) an updated study on the state of the art of cloud trust models; (ii) a taxonomy of characteristics and contributions to cloud trust; (iii) a discussion on works which present hard problems of research on cloud trust models and gaps of contributions in the literature.