Google-managed encryption keys (KMS) and Customer-managed encryption keys (CMEK)

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Google-managed encryption keys (KMS):

• Definition: Encryption keys that are created, managed, and stored entirely by Google within its infrastructure.
• Control: Google has full control over key management operations, including creation, rotation, access, and deletion.
• User involvement: No setup or configuration required by users. Enabled by default for most GCP services that support encryption.
• Visibility: Users cannot directly view or manage these keys.
• Compliance: May not meet the strictest compliance requirements where full key control is mandated.

Customer-managed encryption keys (CMEK):

• Definition: Encryption keys that are created and managed by customers using Google Cloud Key Management Service (Cloud KMS).
• Control: Customers have full control over key management, including creation, rotation, access, storage location, and deletion.
• User involvement: Requires setup and configuration within Cloud KMS.
• Visibility: Customers have full visibility and control over their keys.
• Compliance: Can meet stricter compliance requirements due to customer control over keys.

Here’s a comprehensive comparison of Google-managed encryption keys (KMS) and customer-managed encryption keys (CMEK) within Google Cloud Platform (GCP):

Key Management:

Control and Compliance:

Ease of Use and Cost:

Best Practices for Choosing:

Use Google-managed keys (KMS):

• When you need a simple and cost-effective encryption solution.
• When you trust Google to manage your keys securely.
• When you don’t have strict compliance requirements that mandate full control over keys.

Use customer-managed keys (CMEK):

• When you need more control over key management and access.
• When you have strict compliance requirements that necessitate full key control.
• When you need to meet data residency or locality requirements.
• When you want to restrict Google’s access to your data.

Additional Considerations:

• CMEK is not available for all GCP services. Check the list of supported services.
• Using CMEK can add complexity to your key management processes.
• It’s essential to have a robust key management strategy in place, regardless of the key type you choose.