The CloudTrust Protocol (CTP) is a framework developed by the Cloud Security Alliance that provides a standardized method for requesting and receiving information about cloud service transparency. Released in June 2011, the protocol establishes a structured approach for obtaining fundamental information about essential transparency elements in cloud computing environments. The protocol includes a data model and API specification that defines how transparency information should be requested and delivered. It offers an uncomplicated approach to addressing transparency concerns in cloud services, enabling organizations to systematically gather information about cloud provider practices and security measures. The CloudTrust Protocol is part of the Cloud Security Alliance's broader research initiative to establish standards and best practices for cloud security. Related resources include prototype source code, data model documentation, and API specifications that support implementation of the protocol. The framework addresses the need for standardized transparency mechanisms in cloud computing, allowing organizations to make informed decisions about cloud service providers based on consistent, structured information about their operations and security practices.