Customer-managed encryption keys (CMEK)

By default, Google Cloud automatically encrypts data when it is at rest using encryption keys managed by Google.

If you have specific compliance or regulatory requirements related to the keys that protect your data, you can use customer-managed encryption keys (CMEK) for Document AI. Instead of Google managing the encryption keys that protect your data, your Document AI processor is protected using a key that you control and manage in Cloud Key Management Service (KMS).

This guide describes CMEK for Document AI. For more information about CMEK in general, including when and why to enable it, see the Cloud Key Management Service documentation.

Prerequisite

The Document AI Service Agent must have the Cloud KMS CryptoKey Encrypter/Decrypter role on the key that you use.

The following example grants a role that provides access to a Cloud KMS key:

gcloud

gcloud kms keys add-iam-policy-binding key \
    --keyring key-ring \
    --location location \
    --project key_project_id \
    --member serviceAccount:service-project_number@gcp-sa-prod-dai-core.iam.gserviceaccount.com \
    --role roles/cloudkms.cryptoKeyEncrypterDecrypter

Replace key with the name of the key. Replace key-ring with the name of the key ring where the key is located. Replace location with the Document AI location for the key ring. Replace key_project_id with the project for the key ring. Replace project_number with your project's number.

C#

For more information, see the Document AI C# API reference documentation.

To authenticate to Document AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.


using Google.Cloud.Iam.V1;
using Google.Cloud.Kms.V1;

public class IamAddMemberSample
{
    public Policy IamAddMember(
      string projectId = "my-project", string locationId = "us-east1", string keyRingId = "my-key-ring", string keyId = "my-key",
      string member = "user:foo@example.com")
    {
        // Create the client.
        KeyManagementServiceClient client = KeyManagementServiceClient.Create();

        // Build the resource name.
        CryptoKeyName resourceName = new CryptoKeyName(projectId, locationId, keyRingId, keyId);

        // The resource name could also be a key ring.
        // var resourceName = new KeyRingName(projectId, locationId, keyRingId);

        // Get the current IAM policy.
        Policy policy = client.IAMPolicyClient.GetIamPolicy(
            new GetIamPolicyRequest
            { 
                ResourceAsResourceName = resourceName
            });

        // Add the member to the policy.
        policy.AddRoleMember("roles/cloudkms.cryptoKeyEncrypterDecrypter", member);

        // Save the updated IAM policy.
        Policy result = client.IAMPolicyClient.SetIamPolicy(
            new SetIamPolicyRequest
            {
                ResourceAsResourceName = resourceName,
                Policy = policy
            });

        // Return the resulting policy.
        return result;
    }
}

Go

For more information, see the Document AI Go API reference documentation.

To authenticate to Document AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"context"
	"fmt"
	"io"

	kms "cloud.google.com/go/kms/apiv1"
)

// iamAddMember adds a new IAM member to the Cloud KMS key
func iamAddMember(w io.Writer, name, member string) error {
	// NOTE: The resource name can be either a key or a key ring. If IAM
	// permissions are granted on the key ring, the permissions apply to all keys
	// in the key ring.
	//
	// name := "projects/my-project/locations/us-east1/keyRings/my-key-ring/cryptoKeys/my-key"
	// member := "user:foo@example.com"

	// Create the client.
	ctx := context.Background()
	client, err := kms.NewKeyManagementClient(ctx)
	if err != nil {
		return fmt.Errorf("failed to create kms client: %w", err)
	}
	defer client.Close()

	// Get the current IAM policy.
	handle := client.ResourceIAM(name)
	policy, err := handle.Policy(ctx)
	if err != nil {
		return fmt.Errorf