Implement customer-managed keys for encryption

Customer-managed keys (CMK) provide an added layer of security for data stored in Microsoft Azure Cosmos DB. By using CMK, customers can have control over the encryption keys used to protect their data, enabling them to meet their compliance requirements and ensuring that only authorized entities can access the data. In this article, we will explore how to implement customer-managed keys for encryption in Azure Cosmos DB.

Step 1: Create an Azure Key Vault

First, create an Azure Key Vault in your Azure subscription. You can do this through the Azure portal or by using Azure CLI or PowerShell. Make sure you provide a unique name and select the appropriate subscription and resource group.

Step 2: Configure Key Vault access policies

To enable Azure Cosmos DB to access the keys stored in Azure Key Vault, you need to configure the Key Vault access policies. Add an access policy for Azure Cosmos DB, granting the ‘Get’, ‘Wrap Key’, and ‘Unwrap Key’ permissions to the appropriate service principal or Azure Active Directory (AD) application.

Step 3: Create a Customer-Managed Key

Within Azure Key Vault, create a new customer-managed key. You can create keys either by importing them or by generating them within Azure Key Vault. Ensure that you select the appropriate key type and key size based on your requirements.

Step 4: Enable customer-managed keys in Azure Cosmos DB

Now, it’s time to enable customer-managed keys for Azure Cosmos DB. Go to the Azure Cosmos DB account you wish to configure and navigate to the Encryption blade. Enable the ‘Customer Managed Key’ option and select the Azure Key Vault and customer-managed key you created in the previous steps.

Step 5: Encrypt data using customer-managed keys

With customer-managed keys enabled, Azure Cosmos DB will now use the specified key for encrypting data at rest. Any newly created or updated data will be automatically encrypted using the customer-managed key. It’s important to note that Azure Cosmos DB handles the key rotation and updating of encryption settings seamlessly without any additional effort required from the user.

Step 6: Access data using customer-managed keys

To access the data encrypted with customer-managed keys, the appropriate access policies and permissions need to be granted. This can be done by configuring the necessary Key Vault access policies for the entities that require access to the encrypted data.

In conclusion, implementing customer-managed keys for encryption in Azure Cosmos DB provides an additional layer of control and security for your data. By leveraging Azure Key Vault integration, you can ensure that the encryption keys used to protect your data remain in your control, enabling you to meet your compliance requirements. Follow the steps outlined in this article to securely implement customer-managed keys for encryption in Azure Cosmos DB.