De-identify and re-identify sensitive data

De-identify and re-identify sensitive data

This quickstart shows you how to use Cloud Data Loss Prevention to de-identify and re-identify sensitive data in text content. In the process, it takes you through using Cloud Key Management Service to create a wrapped key. You need this key in your de-identify and re-identify requests.

The process described in this quickstart is called pseudonymization (or tokenization). In this process, Cloud DLP uses a cryptographic key to convert (de-identify) sensitive text into a token. In order to restore (re-identify) that text, you need the cryptographic key that you used during de-identification and the token.

Cloud DLP supports both reversible and non-reversible cryptographic methods. In order to re-identify content, you need to choose a reversible method.

The cryptographic method described here is called deterministic encryption using AES-SIV (Advanced Encryption Standard in Synthetic Initialization Vector mode). We recommend this among all the reversible cryptographic methods that Cloud DLP supports, because it provides the highest level of security.

You can complete the steps in this topic in 10 to 20 minutes, not including the Before you begin steps.

Note: When you use Cloud KMS for cryptographic operations, charges apply.

Before you begin

1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
2. Install the Google Cloud CLI.

3. To initialize the gcloud CLI, run the following command:

   gcloud init

4. Create or select a Google Cloud project.

   Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

   • Create a Cloud project:

     gcloud projects create PROJECT_ID

   • Select the Cloud project that you created:

     gcloud config set project PROJECT_ID

5. Make sure that billing is enabled for your Cloud project. Learn how to check if billing is enabled on a project.

6. Enable the Cloud DLP and Cloud KMS APIs:

   gcloud services enable dlp.googleapis.com cloudkms.googleapis.com

7. Grant roles to your Google Account. Run the following command once for each of the following IAM roles: roles/dlp.user

   gcloud projects add-iam-policy-binding PROJECT_ID --member="user:EMAIL_ADDRESS" --role=ROLE

   • Replace PROJECT_ID with your project ID.
   • Replace EMAIL_ADDRESS with your email address.
   • Replace ROLE with each individual role.
8. Install the Google Cloud CLI.

9. To initialize the gcloud CLI, run the following command:

   gcloud init

10. Create or select a Google Cloud project.

    Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

    • Create a Cloud project:

      gcloud projects create PROJECT_ID

    • Select the Cloud project that you created:

      gcloud config set project PROJECT_ID

11. Make sure that billing is enabled for your Cloud project. Learn how to check if billing is enabled on a project.

12. Enable the Cloud DLP and Cloud KMS APIs:

    gcloud services enable dlp.googleapis.com cloudkms.googleapis.com

13. Grant roles to your Google Account. Run the following command once for each of the following IAM roles: roles/dlp.user

    gcloud projects add-iam-policy-binding PROJECT_ID --member="user:EMAIL_ADDRESS" --role=ROLE

    • Replace PROJECT_ID with your project ID.
    • Replace EMAIL_ADDRESS with your email address.
    • Replace ROLE with each individual role.

Step 1: Create a key ring and a key

Before you start this procedure, decide where you want Cloud DLP to process your de-identification and re-identification requests. When you create a Cloud KMS key, you must store it in either global or in the same region that you will use for your Cloud DLP requests. Otherwise, the Cloud DLP requests will fail.

You can find a list of supported locations in Cloud DLP locations. Take note of the name of your chosen region (for example, us-west1).

This procedure uses global as the location for all API requests. If you want to use a different region, replace global with the region name.

1. Create a key ring:

   gcloud kms keyrings create "dlp-keyring" \
       --location "global"
   

2. Create a key:

   gcloud kms keys create "dlp-key" \
       --location "global" \
       --keyring "dlp-keyring" \
       --purpose "encryption"
   

3. List your key ring and key:

   gcloud kms keys list \
       --location "global" \
       --keyring "dlp-keyring"
   

   You get the following output:

   NAME                                                                                   PURPOSE          ALGORITHM                    PROTECTION_LEVEL  LABELS  PRIMARY_ID  PRIMARY_STATE
   projects/PROJECT_ID/locations/global/keyRings/dlp-keyring/cryptoKeys/dlp-key  ENCRYPT_DECRYPT  GOOGLE_SYMMETRIC_ENCRYPTION  SOFTWARE                  1           ENABLED
   

   In this output, PROJECT_ID is the ID of your project.

   The path under NAME is the full resource name of your Cloud KMS key. Take note of it because the de-identify and re-identify requests require it.

Step 2: Create a base64-encoded AES key

This section describes how to create an Advanced Encryption Standard (AES) key and encode it in base64 format.

Note: These steps use the openssl and base64 commands, but there are many other ways to perform this task.

1. Create a 128-, 192-, or 256-bit AES key. The following command uses openssl to create a 256-bit key in the current directory:

   openssl rand -out "./aes_key.bin" 32
   

   The file aes_key.bin is added to your current directory.

2. Encode the AES key as a base64 string:

   base64 -i ./aes_key.bin
   

   You get an output similar to the following:

   uEDo6/yKx+zCg2cZ1DBwpwvzMVNk/c+jWs7OwpkMc/s=
   

   Warning: Do not use this example key to protect actual sensitive workloads. This key is provided only to serve as an example. Because it's shared here, this key is not safe to use.

Step 3: Wrap the AES key using the Cloud KMS key

This section describes how to use the Cloud KMS key that you created in Step 1 to wrap the base64-encoded AES key that you created in Step 2.

To wrap the AES key, use curl to send the following request to the Cloud KMS API projects.locations.keyRings.cryptoKeys.encrypt:

curl "https://cloudkms.googleapis.com/v1/projects/PROJECT_ID/locations/global/keyRings/dlp-keyring/cryptoKeys/dlp-key:encrypt" \
  --request "POST" \
  --header "Authorization:Bearer $(gcloud auth application-default print-access-token)" \
  --header "content-type: application/json" \
  --data "{\"plaintext\": \"BASE64_ENCODED_AES_KEY\"}"

Replace the following:

• PROJECT_ID: the ID of your project.
• BASE64_ENCODED_AES_KEY: the base64-encoded string returned in Step 2.

The response that you get from Cloud KMS is similar to the following JSON:

{
  "name": "projects/PROJECT_ID/locations/global/keyRings/dlp-keyring/cryptoKeys/dlp-key/cryptoKeyVersions/1",
  "ciphertext": "CiQAYuuIGo5DVaqdE0YLioWxEhC8LbTmq7Uy2G3qOJlZB7WXBw0SSQAjdwP8ZusZJ3Kr8GD9W0vaFPMDksmHEo6nTDaW/j5sSYpHa1ym2JHk+lUgkC3Zw5bXhfCNOkpXUdHGZKou1893O8BDby/82HY=",
  "ciphertextCrc32c": "901327763",
  "protectionLevel": "SOFTWARE"
}

In this output, PROJECT_ID is the ID of your project.

Take note of the value of ciphertext in the response that you get. That is your wrapped key.

Step 4: Send a de-identify request to the DLP API

This section describes how to de-identify sensitive data in text content.

To complete this task, you need the following:

• The full resource name of the Cloud KMS key that you created in Step 1.
• The wrapped key that you created in Step 3.

This section requires you to save the sample request in a JSON file. If you're using Cloud Shell, you can use the Cloud Shell Editor to create the file. To launch the editor, click Open Editor on the toolbar of the Cloud Shell window.

To de-identify sensitive data in text content, follow these steps:

1. Create a JSON request file with the following text.

   {
     "item": {
       "value": "My name is Alicia Abernathy, and my email address is [e-mail]."
     },
     "deidentifyConfig": {
       "infoTypeTransformations": {
         "transformations": [
           {
             "infoTypes": [
               {
                 "name": "EMAIL_ADDRESS"
               }
             ],
             "primitiveTransformation": {
               "cryptoDeterministicConfig": {
                 "cryptoKey": {
                   "kmsWrapped": {
                     "cryptoKeyName": "projects/PROJECT_ID/locations/global/keyRings/dlp-keyring/cryptoKeys/dlp-key",
                     "wrappedKey": "WRAPPED_KEY"
                   }
                 },
                 "surrogateInfoType": {
                   "name": "EMAIL_ADDRESS_TOKEN"
                 }
               }
             }
           }
         ]
       }
     },
     "inspectConfig": {
       "infoTypes": [
         {
           "name": "EMAIL_ADDRESS"
         }
       ]
     }
   }
   

   Replace the following:

   • PROJECT_ID: the ID of your project.
   • WRAPPED_KEY: the wrapped key that you created in Step 3.

   Make sure that the resulting value of cryptoKeyName forms the full resource name of your Cloud KMS key.

   For more information on the components of this JSON request, see projects.locations.content.deidentify. After you complete this quickstart, try experimenting with different inputs for this request. You can use curl as described here. Alternatively, you can use the API Explorer on that API reference page under Try this API.

2. Save the file as deidentify-request.json.

3. Use curl to make a projects.locations.content.deidentify request:

   curl -s \
   -H "Authorization: Bearer $(gcloud auth application-default print-access-token)" \
   -H "Content-Type: application/json" \
   https://dlp.googleapis.com/v2/projects/PROJECT_ID/locations/global/content:deidentify \
   -d @deidentify-request.json
   

   Replace PROJECT_ID with the ID of your project.

   To pass a filename to curl you use the -d option (for data) and precede the filename with an @ sign. This file must be in the same directory where you execute the curl command.

   Note: This example request explicitly targets the global location. This is the same as calling the projects.content.deidentify API, which defaults to the global location.

   The response that you get from Cloud DLP is similar to the following JSON:

   {
    "item": {
      "value": "My name is Alicia Abernathy, and my email address is EMAIL_ADDRESS_TOKEN(52):AVAx2eIEnIQP5jbNEr2j9wLOAd5m4kpSBR/0jjjGdAOmryzZbE/q."
    },
    "overview": {
      "transformedBytes": "22",
      "transformationSummaries": [
        {
          "infoType": {
            "name": "EMAIL_ADDRESS"
          },
          "transformation": {
            "cryptoDeterministicConfig": {
              "cryptoKey": {
                "kmsWrapped": {
                  "wrappedKey": "CiQAYuuIGo5DVaqdE0YLioWxEhC8LbTmq7Uy2G3qOJlZB7WXBw0SSQAjdwP8ZusZJ3Kr8GD9W0vaFPMDksmHEo6nTDaW/j5sSYpHa1ym2JHk+lUgkC3Zw5bXhfCNOkpXUdHGZKou1893O8BDby/82HY=",
                  "cryptoKeyName": "projects/PROJECT_ID/locations/global/keyRings/dlp-keyring/cryptoKeys/dlp-key"
                }
              },
              "surrogateInfoType": {
                "name": "EMAIL_ADDRESS_TOKEN"
              }
            }
          },
          "results": [
            {
              "count": "1",
              "code": "SUCCESS"
            }
          ],
          "transformedBytes": "22"
        }
      ]
    }
   }
   

   In the item field, the email address is replaced with a token like EMAIL_ADDRESS_TOKEN(52):AVAx2eIEnIQP5jbNEr2j9wLOAd5m4kpSBR/0jjjGdAOmryzZbE/q. To re-identify this content, you must pass the entire token in the re-identify request.

Step 5: Send a re-identify request to the DLP API

This section describes how to re-identify tokenized data in text content.

To complete this task, you need the following:

• The full resource name of the Cloud KMS key that you created in Step 1.
• The wrapped key that you created in Step 3.
• The token that you received in Step 4.

To re-identify tokenized content, follow these steps:

1. Create a JSON request file with the following text.

   {
     "reidentifyConfig":{
       "infoTypeTransformations":{
         "transformations":[
           {
             "infoTypes":[
               {
                 "name":"EMAIL_ADDRESS_TOKEN"
               }
             ],
             "primitiveTransformation":{
               "cryptoDeterministicConfig":{
                 "cryptoKey":{
                 "kmsWrapped": {
                   "cryptoKeyName": "projects/PROJECT_ID/locations/global/keyRings/dlp-keyring/cryptoKeys/dlp-key",
                   "wrappedKey": "WRAPPED_KEY"
                 }
               },
                 "surrogateInfoType":{
                   "name":"EMAIL_ADDRESS_TOKEN"
                 }
               }
             }
           }
         ]
       }
     },
     "inspectConfig":{
       "customInfoTypes":[
         {
           "infoType":{
             "name":"EMAIL_ADDRESS_TOKEN"
           },
           "surrogateType":{
   
           }
         }
       ]
     },
     "item":{
       "value": "My name is Alicia Abernathy, and my email address is TOKEN."
     }
   }
   

   Replace the following:

   • PROJECT_ID: the ID of your project.
   • WRAPPED_KEY: the wrapped key that you created in Step 3.
   • TOKEN: the token that you received in Step 4—for example, EMAIL_ADDRESS_TOKEN(52):AVAx2eIEnIQP5jbNEr2j9wLOAd5m4kpSBR/0jjjGdAOmryzZbE/q.

   Make sure that the resulting value of cryptoKeyName forms the full resource name of your Cloud KMS key.

   For more information on the components of this JSON request, see projects.locations.content.reidentify. After you complete this quickstart, try experimenting with different inputs for this request. You can use curl as described here. Alternatively, you can use the API Explorer on that API reference page under Try this API.

2. Save the file as reidentify-request.json.

3. Use curl to make a projects.locations.content.reidentify request:

   curl -s \
   -H "Authorization: Bearer $(gcloud auth application-default print-access-token)" \
   -H "Content-Type: application/json" \
   https://dlp.googleapis.com/v2/projects/PROJECT_ID/locations/global/content:reidentify \
   -d @reidentify-request.json
   

   Replace PROJECT_ID with the ID of your project.

   To pass a filename to curl you use the -d option (for data) and precede the filename with an @ sign. This file must be in the same directory where you execute the curl command.

   Note: This example request explicitly targets the global location. This is the same as calling the projects.content.reidentify API, which defaults to the global location.

   The response that you get from Cloud DLP is similar to the following JSON:

   {
    "item": {
      "value": "My name is Alicia Abernathy, and my email address is [e-mail]."
    },
    "overview": {
      "transformedBytes": "70",
      "transformationSummaries": [
        {
          "infoType": {
            "name": "EMAIL_ADDRESS"
          },
          "transformation": {
            "cryptoDeterministicConfig": {
              "cryptoKey": {
                "kmsWrapped": {
                  "wrappedKey": "CiQAYuuIGo5DVaqdE0YLioWxEhC8LbTmq7Uy2G3qOJlZB7WXBw0SSQAjdwP8ZusZJ3Kr8GD9W0vaFPMDksmHEo6nTDaW/j5sSYpHa1ym2JHk+lUgkC3Zw5bXhfCNOkpXUdHGZKou1893O8BDby/82HY=",
                  "cryptoKeyName": "projects/PROJECT_ID/locations/global/keyRings/dlp-keyring/cryptoKeys/dlp-key"
                }
              },
              "surrogateInfoType": {
                "name": "EMAIL_ADDRESS_TOKEN"
              }
            }
          },
          "results": [
            {
              "count": "1",
              "code": "SUCCESS"
            }
          ],
          "transformedBytes": "70"
        }
      ]
    }
   }
   

   In the item field, the email address token is replaced with the actual email address from the original text.

   You've just de-identified and re-identified sensitive data in text content using deterministic encryption.

Clean up

To avoid incurring charges to your Google Cloud account for the resources used on this page, delete the Cloud project with the resources.

Destroy your key version

If you no longer want to use the key you created in this quickstart, destroy its version.

Warning: When you destroy a key version, you can no longer decrypt content that was encrypted using that version of the key. Make sure that you no longer need a key version before you destroy it.

List the versions available for your key:

gcloud kms keys versions list \
    --location "global" \
    --keyring "dlp-keyring" \
    --key "dlp-key"

To destroy a version, run the following command:

gcloud kms keys versions destroy KEY_VERSION \
    --location "global" \
    --keyring "dlp-keyring" \
    --key "dlp-key"

Replace KEY_VERSION with the number of the version to be destroyed.

Delete the project

If you created a new project for this quickstart, the easiest way to prevent additional charges is to delete the project.

Caution: Deleting a project has the following effects:

• Everything in the project is deleted. If you used an existing project for this tutorial, when you delete it, you also delete any other work you've done in the project.
• Custom project IDs are lost. When you created this project, you might have created a custom project ID that you want to use in the future. To preserve the URLs that use the project ID, such as an appspot.com URL, delete selected resources inside the project instead of deleting the whole project.

If you plan to explore multiple tutorials and quickstarts, reusing projects can help you avoid exceeding project quota limits.

Delete a Cloud project:

gcloud projects delete PROJECT_ID

Revoke your credentials

Optional: Revoke credentials from the gcloud CLI.

gcloud auth revoke

What's next

• For more in-depth information on how to de-identify sensitive content, see De-identifying sensitive data.
• For information on how a de-identification workflow fits into real-life deployments, see De-identification and re-identification of PII in large-scale datasets using Cloud DLP.
• For conceptual information on tokenizing data through a cryptographic key, see Pseudonymization.