adding key information

Author: Larry Franks

articles/machine-learning/concept-enterprise-security.md

@@ -135,6 +135,8 @@ For information on how to use your own keys for data stored in Azure Blob storag
 
 Training data is typically also stored in Azure Blob storage so that it's accessible to training compute targets. This storage isn't managed by Azure Machine Learning but mounted to compute targets as a remote file system.
 
+If you need to __rotate or revoke__ your key, you can do so at any time. When rotating a key, the storage account will start using the new key (latest version) to encrypt data at rest. When revoking (disabling) a key, the storage account takes care of failing requests. It usually takes an hour for the rotation or revocation to be effective.
+
 For information on regenerating the access keys, see [Regenerate storage access keys](how-to-change-storage-access-key.md).
 
 #### Azure Cosmos DB
@@ -171,6 +173,8 @@ This Cosmos DB instance is created in a Microsoft-managed resource group in your
 > * If you need to delete this Cosmos DB instance, you must delete the Azure Machine Learning workspace that uses it. 
 > * The default [__Request Units__](../cosmos-db/request-units.md) for this Cosmos DB account is set at __8000__. Changing this value is unsupported. 
 
+If you need to __rotate or revoke__ your key, you can do so at any time. When rotating a key, Cosmos DB will start using the new key (latest version) to encrypt data at rest. When revoking (disabling) a key, Cosmos DB takes care of failing requests. It usually takes an hour for the rotation or revocation to be effective.
+
 For more information on customer-managed keys with Cosmos DB, see [Configure customer-managed keys for your Azure Cosmos DB account](../cosmos-db/how-to-setup-cmk.md).
 
 #### Azure Container Registry