Cloud Computing Compliance Controls Catalog (C5)
In 2016, the German Federal Office for Information Security (Bundesamt für Sicherheit in der Informationstechnik, or BSI) created the Cloud Computing Compliance Controls Catalog (C5). C5 is an audited standard that establishes a mandatory minimum baseline for cloud security and the adoption of public cloud solutions by German government agencies and organizations that work with government. C5 is also being increasingly adopted by the private sector.
The purpose of the C5 catalog of requirements is to provide a consistent security framework for certifying cloud service providers and to give customers assurance that their data will be managed securely.
C5 is based on internationally recognized IT security standards like ISO/IEC 27001:2013, the Cloud Security Alliance Cloud Controls Matrix 3.0.1, and BSI’s own IT-Grundschutz Catalogues. The catalog consists of 114 requirements across 17 domains, for example, the organization of information security and physical security, with security requirements basic to all cloud service providers, and other requirements for processing highly confidential data and situations requiring high availability.
The BSI also puts emphasis on transparency. As part of an audit, the cloud provider must include a detailed system description and disclose environmental parameters like jurisdiction and data processing location, provision of services, and other certifications issued to the cloud services, and information about the cloud provider’s disclosure obligations to public authorities. This helps potential cloud customers decide whether the cloud services meet their essential requirements such as compliance with legal requirements like data protection, company policies, or the ability to address the threat of industrial espionage.