Cloud Computing Compliance Controls Catalog (C5)

C5 (Cloud Computing Compliance Controls Catalogue) is the “cloud computing IT-Security” standard in Germany. Designed and first released by the BSI in 2016, the C5 control set offers additional assurance to customers in Germany as they move their complex and regulated workloads to Cloud Computing Service providers such as AWS.

The current C5 was released in 2020 and includes requirements from the following standards and publications:

• ISO/IEC 27001:2013 – Information security management systems – Requirements
• ISO/IEC-27002:2016 – IT security procedures – Guidelines for information security measures
• ISO/IEC 27017:2015 – Security techniques – Code of practice for information security controls based on ISO/IEC 27002 for cloud services
• BSI – IT-Grundschutz-Kompendium, 2nd Edition 2019
• CSA – Cloud Controls Matrix 3.0.1 (CSA - Cloud Security Alliance)
• AICPA Trust Service Principles Criteria 2017 (AICPA - American Institute of Certified Public Accountants)
• ANSSI (Agence nationale de la sécurité des systèmes d’information, National Cybersecurity Agency of France) – Providers of cloud computing services v. 3.1 (SecNumCloud)
• IDW (Institut der Wirtschaftsprüfer, the German Institute of Certified Public Accountants) RS FAIT 5 – Statement on Financial Reporting: “Principles of Orderly Accounting for the Outsourcing of Financial Reporting-Related Services including Cloud Computing”, as at November 4, 2015

Germany’s national cybersecurity authority Bundesamt für Sicherheit in der Informationstechnik (BSI) developed the C5 standard in 2016. The BSI defines the IT-Security requirements for all governmental systems, and most German companies align their IT-Security strategy with BSI standards. The BSI reworked and updated the C5 catalogue in 2019. A new version (C5:2020) was finalised in January 2020.

The C5 report provides our European customers with an independent third-party attestation on the suitability of the design and operational effectiveness of our controls to meet the C5 basic and additional criteria. Specifically in Germany, customers are used to looking for cloud services which are assessed against the C5 criteria. C5 provides customers with a framework documenting an  IT-Security level equivalent to the IT-Grundschutz covering all IT-Security aspects for Cloud Computing. For federal authorities, a C5 attestation is a basic requirement in the procurement process.

Current information on C5 at AWS can be reviewed on the respective AWS Security Blog C5 posts.

AWS Regions in scope for C5 include Frankfurt, Ireland, London, Paris, Milan, Stockholm, Singapore, Zurich and Spain, as well as Edge locations in Germany, Ireland, England, France, Singapore, Sweden, Italy, Spain and Switzerland.

The covered AWS services that are already in scope for C5 can be found within AWS Services in Scope by Compliance Program. If you would like to learn more about using these services and/or have interest in other services please contact us.

The AWS C5 report is available to customers by using AWS Artifact, a self-service portal for on-demand access to AWS compliance reports. Sign in to AWS Artifact in the AWS Management Console, or learn more at Getting Started with AWS Artifact.

BSI has aligned this work with ANSSI and their upcoming SecNumCloud Label. The C5 standard has been influenced by and, in turn, has influenced the SecNumCloud standard in France, with the clear goal to have the option for mutual recognition under a common label called ESCloud. Also, the draft version of the European Union Agency for Cybersecurity (ENISA)’s European Union Cybersecurity Certification Scheme for Cloud Services (EUCS) draws significantly from C5’s security standard.

A certification is issued by an accredited specialized company and often lasts between one and three years. An attestation can be received during a compliance audit or an accounting audit by qualified personnel. An attestation focuses more on the continuous implementation aspect, which means that the re-audit cycle is much shorter – down to 6 months. According to ISAE 3000 / 3402, the audit process delivers evidence of appropriateness and effectiveness over a past range of time. A certification is just a snapshot in time.