  Cloud computing represents a significant economic opportunity for Europe.
However, this growth is threatened by adoption barriers largely related to
trust. This position paper examines trust and confidence issues in cloud
computing and advances a case for addressing them through the implementation of
a novel trustmark scheme for cloud service providers. The proposed trustmark
would be both active and dynamic featuring multi-modal information about the
performance of the underlying cloud service. The trustmarks would be informed
by live performance data from the cloud service provider, or ideally an
independent third-party accountability and assurance service that would
communicate up-to-date information relating to service performance and
dependability. By combining assurance measures with a remediation scheme, cloud
service providers could both signal dependability to customers and the wider
marketplace and provide customers, auditors and regulators with a mechanism for
determining accountability in the event of failure or non-compliance. As a
result, the trustmarks would convey to consumers of cloud services and other
stakeholders that strong assurance and accountability measures are in place for
the service in question and thereby address trust and confidence issues in
cloud computing.
