CRY · Cryptography and Key Management
CRY-19 Secure Handling of Customer Managed Keys
New in C5:2026
Basic criterion
The cloud service provider implements procedures and technical safeguards to ensure the secure handling of cryptographic keys managed by cloud service customers. In these procedures, the following aspects are considered:
- Secure integration of customer-generated keys ('Bring-Your-Own-Key'; BYOK) into the cloud environment;
- Logging of all activities related to customer-managed keys; and
- Definition of access control mechanisms to enable that only authorised users can gain access to customer-managed keys.
Complementary customer criteria
What cloud service customers implement on their side.
Cloud service customers ensure with suitable controls that their agreements with the cloud service provider include robust procedures and technical safeguards for the secure handling of customer-managed cryptographic keys. Cloud service customers ensure that these procedures address the secure integration of their keys into the cloud environment, comprehensive logging of all activities related to their keys, and clearly defined access control mechanisms to restrict access solely to authorised users.
Related criteria
BSI text from C5:2026 and its changelog: © Federal Office for Information Security 2026, reproduced unchanged under CC BY-ND 4.0. Unofficial site, not affiliated with BSI. Licence and sources