3.9 Ensure storage for critical data are encrypted with Customer Managed Key

Information

Enable sensitive data encryption at rest using Customer Managed Keys rather than Microsoft Managed keys

Rationale:

By default, data in the storage account is encrypted using Microsoft Managed Keys at rest. All Azure Storage resources are encrypted, including blobs, disks, files, queues, and tables. All object metadata is also encrypted. However, if you want to control and manage this encryption key yourself, you can specify a customer-managed key, that key is used to protect and control access to the key that encrypts your data. You can also choose to automatically update the key version used for Azure Storage encryption whenever a new version is available in the associated Key Vault.

Impact:

If the key expires by setting the 'activation date' and 'expiration date' of the key, the user must rotate the key manually.

Using Customer Managed Keys may also incur additional man-hour requirements to create, store, manage, and protect the keys as needed.

Solution

From Azure Console:

Go to Storage Accounts

For each storage account, go to Encryption

Set Customer Managed Keys

Select the Encryption key and enter the appropriate setting value

Click Save

Default Value:

By default, Encryption type is set to Microsoft Managed Keys

See Also

https://workbench.cisecurity.org/files/3459

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

References: 800-53|IA-5(1), CSCv7|14.8

Plugin: microsoft_azure

Control ID: 4ccd977ba3851a7e9ce32b49f587ab88714933403246304a7f4f3478a5da9736