Format-preserving encryption (FPE)

Demonstrates encrypting sensitive characters while maintaining format.

Documentation pages that include this code sample

To view the code sample used in context, see the following documentation:

Code sample

C#

To learn how to install and use the client library for Cloud DLP, see Cloud DLP client libraries.


using System;
using System.Collections.Generic;
using Google.Api.Gax.ResourceNames;
using Google.Cloud.Dlp.V2;
using Google.Protobuf;
using static Google.Cloud.Dlp.V2.CryptoReplaceFfxFpeConfig.Types;

public class DeidentifyWithFpe
{
    public static DeidentifyContentResponse Deidentify(
        string projectId,
        string dataValue,
        IEnumerable<InfoType> infoTypes,
        string keyName,
        string wrappedKey,
        FfxCommonNativeAlphabet alphabet)
    {
        var deidentifyConfig = new DeidentifyConfig
        {
            InfoTypeTransformations = new InfoTypeTransformations
            {
                Transformations =
                {
                    new InfoTypeTransformations.Types.InfoTypeTransformation
                    {
                        PrimitiveTransformation = new PrimitiveTransformation
                        {
                            CryptoReplaceFfxFpeConfig = new CryptoReplaceFfxFpeConfig
                            {
                                CommonAlphabet = alphabet,
                                CryptoKey = new CryptoKey
                                {
                                    KmsWrapped = new KmsWrappedCryptoKey
                                    {
                                        CryptoKeyName = keyName,
                                        WrappedKey = ByteString.FromBase64 (wrappedKey)
                                    }
                                },
                                SurrogateInfoType = new InfoType
                                {
                                    Name = "TOKEN"
                                }
                            }
                        }
                    }
                }
            }
        };

        var dlp = DlpServiceClient.Create();
        var response = dlp.DeidentifyContent(
            new DeidentifyContentRequest
            {
                Parent = new LocationName(projectId, "global").ToString(),
                InspectConfig = new InspectConfig
                {
                    InfoTypes = { infoTypes }
                },
                DeidentifyConfig = deidentifyConfig,
                Item = new ContentItem { Value = dataValue }
            });

        Console.WriteLine($"Deidentified content: {response.Item.Value}");
        return response;
    }
}

Go

To learn how to install and use the client library for Cloud DLP, see Cloud DLP client libraries.

import (
	"context"
	"fmt"
	"io"
	"io/ioutil"

	dlp "cloud.google.com/go/dlp/apiv2"
	dlppb "google.golang.org/genproto/googleapis/privacy/dlp/v2"
)

// deidentifyFPE deidentifies the input with FPE (Format Preserving Encryption).
// keyFileName is the file name with the KMS wrapped key and cryptoKeyName is the
// full KMS key resource name used to wrap the key. surrogateInfoType is an
// optional identifier needed for reidentification. surrogateInfoType can be any
// value not found in your input.
// Info types can be found with the infoTypes.list method or on https://cloud.google.com/dlp/docs/infotypes-reference
func deidentifyFPE(w io.Writer, projectID, input string, infoTypeNames []string, keyFileName, cryptoKeyName, surrogateInfoType string) error {
	// projectID := "my-project-id"
	// input := "My SSN is 123456789"
	// infoTypeNames := []string{"US_SOCIAL_SECURITY_NUMBER"}
	// keyFileName := "projects/YOUR_GCLOUD_PROJECT/locations/YOUR_LOCATION/keyRings/YOUR_KEYRING_NAME/cryptoKeys/YOUR_KEY_NAME"
	// cryptoKeyName := "YOUR_ENCRYPTED_AES_256_KEY"
	// surrogateInfoType := "AGE"
	ctx := context.Background()
	client, err := dlp.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("dlp.NewClient: %v", err)
	}
	defer client.Close()
	// Convert the info type strings to a list of InfoTypes.
	var infoTypes []*dlppb.InfoType
	for _, it := range infoTypeNames {
		infoTypes = append(infoTypes, &dlppb.InfoType{Name: it})
	}
	// Read the key file.
	keyBytes, err := ioutil.ReadFile(keyFileName)
	if err != nil {
		return fmt.Errorf("ReadFile: %v", err)
	}
	// Create a configured request.
	req := &dlppb.DeidentifyContentRequest{
		Parent: fmt.Sprintf("projects/%s/locations/global", projectID),
		InspectConfig: &dlppb.InspectConfig{
			InfoTypes: infoTypes,
		},
		DeidentifyConfig: &dlppb.DeidentifyConfig{
			Transformation: &dlppb.DeidentifyConfig_InfoTypeTransformations{
				InfoTypeTransformations: &dlppb.InfoTypeTransformations{
					Transformations: []*dlppb.InfoTypeTransformations_InfoTypeTransformation{
						{
							InfoTypes: []*dlppb.InfoType{}, // Match all info types.
							PrimitiveTransformation: &dlppb.PrimitiveTransformation{
								Transformation: &dlppb.PrimitiveTransformation_CryptoReplaceFfxFpeConfig{
									CryptoReplaceFfxFpeConfig: &dlppb.CryptoReplaceFfxFpeConfig{
										CryptoKey: &dlppb.CryptoKey{
											Source: &dlppb.CryptoKey_KmsWrapped{
												KmsWrapped: &dlppb.KmsWrappedCryptoKey{
													WrappedKey:    keyBytes,
													CryptoKeyName: cryptoKeyName,
												},
											},
										},
										// Set the alphabet used for the output.
										Alphabet: &dlppb.CryptoReplaceFfxFpeConfig_CommonAlphabet{
											CommonAlphabet: dlppb.CryptoReplaceFfxFpeConfig_ALPHA_NUMERIC,
										},
										// Set the surrogate info type, used for reidentification.
										SurrogateInfoType: &dlppb.InfoType{
											Name: surrogateInfoType,
										},
									},
								},
							},
						},
					},
				},
			},
		},
		// The item to analyze.
		Item: &dlppb.ContentItem{
			DataItem: &dlppb.ContentItem_Value{
				Value: input,
			},
		},
	}
	// Send the request.
	r, err := client.DeidentifyContent(ctx, req)
	if err != nil {
		return fmt.Errorf("DeidentifyContent: %v", err)
	}
	// Print the result.
	fmt.Fprint(w, r.GetItem().GetValue())
	return nil
}

Java

To learn how to install and use the client library for Cloud DLP, see Cloud DLP client libraries.


import com.google.cloud.dlp.v2.DlpServiceClient;
import com.google.common.io.BaseEncoding;
import com.google.privacy.dlp.v2.ContentItem;
import com.google.privacy.dlp.v2.CryptoKey;
import com.google.privacy.dlp.v2.CryptoReplaceFfxFpeConfig;
import com.google.privacy.dlp.v2.CryptoReplaceFfxFpeConfig.FfxCommonNativeAlphabet;
import com.google.privacy.dlp.v2.DeidentifyConfig;
import com.google.privacy.dlp.v2.DeidentifyContentRequest;
import com.google.privacy.dlp.v2.DeidentifyContentResponse;
import com.google.privacy.dlp.v2.InfoType;
import com.google.privacy.dlp.v2.InfoTypeTransformations;
import com.google.privacy.dlp.v2.InfoTypeTransformations.InfoTypeTransformation;
import com.google.privacy.dlp.v2.InspectConfig;
import com.google.privacy.dlp.v2.KmsWrappedCryptoKey;
import com.google.privacy.dlp.v2.LocationName;
import com.google.privacy.dlp.v2.PrimitiveTransformation;
import com.google.protobuf.ByteString;
import java.io.IOException;
import java.util.Arrays;

public class DeIdentifyWithFpe {

  public static void main(String[] args) throws Exception {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "your-project-id";
    String textToDeIdentify = "I'm Gary and my email is gary@example.com";
    String kmsKeyName =
        "projects/YOUR_PROJECT/"
            + "locations/YOUR_KEYRING_REGION/"
            + "keyRings/YOUR_KEYRING_NAME/"
            + "cryptoKeys/YOUR_KEY_NAME";
    String wrappedAesKey = "YOUR_ENCRYPTED_AES_256_KEY";
    deIdentifyWithFpe(projectId, textToDeIdentify, kmsKeyName, wrappedAesKey);
  }

  public static void deIdentifyWithFpe(
      String projectId, String textToDeIdentify, String kmsKeyName, String wrappedAesKey)
      throws IOException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (DlpServiceClient dlp = DlpServiceClient.create()) {
      // Specify what content you want the service to DeIdentify
      ContentItem contentItem = ContentItem.newBuilder().setValue(textToDeIdentify).build();

      // Specify the type of info the inspection will look for.
      // See https://cloud.google.com/dlp/docs/infotypes-reference for complete list of info types
      InfoType infoType = InfoType.newBuilder().setName("US_SOCIAL_SECURITY_NUMBER").build();
      InspectConfig inspectConfig =
          InspectConfig.newBuilder().addAllInfoTypes(Arrays.asList(infoType)).build();

      // Specify an encrypted AES-256 key and the name of the Cloud KMS key that encrypted it
      KmsWrappedCryptoKey kmsWrappedCryptoKey =
          KmsWrappedCryptoKey.newBuilder()
              .setWrappedKey(ByteString.copyFrom(BaseEncoding.base64().decode(wrappedAesKey)))
              .setCryptoKeyName(kmsKeyName)
              .build();
      CryptoKey cryptoKey = CryptoKey.newBuilder().setKmsWrapped(kmsWrappedCryptoKey).build();

      // Specify how the info from the inspection should be encrypted.
      InfoType surrogateInfoType = InfoType.newBuilder().setName("SSN_TOKEN").build();
      CryptoReplaceFfxFpeConfig cryptoReplaceFfxFpeConfig =
          CryptoReplaceFfxFpeConfig.newBuilder()
              .setCryptoKey(cryptoKey)
              // Set of characters in the input text. For more info, see
              // https://cloud.google.com/dlp/docs/reference/rest/v2/organizations.deidentifyTemplates#DeidentifyTemplate.FfxCommonNativeAlphabet
              .setCommonAlphabet(FfxCommonNativeAlphabet.NUMERIC)
              .setSurrogateInfoType(surrogateInfoType)
              .build();
      PrimitiveTransformation primitiveTransformation =
          PrimitiveTransformation.newBuilder()
              .setCryptoReplaceFfxFpeConfig(cryptoReplaceFfxFpeConfig)
              .build();
      InfoTypeTransformation infoTypeTransformation =
          InfoTypeTransformation.newBuilder()
              .setPrimitiveTransformation(primitiveTransformation)
              .build();
      InfoTypeTransformations transformations =
          InfoTypeTransformations.newBuilder().addTransformations(infoTypeTransformation).build();

      DeidentifyConfig deidentifyConfig =
          DeidentifyConfig.newBuilder().setInfoTypeTransformations(transformations).build();

      // Combine configurations into a request for the service.
      DeidentifyContentRequest request =
          DeidentifyContentRequest.newBuilder()
              .setParent(LocationName.of(projectId, "global").toString())
              .setItem(contentItem)
              .setInspectConfig(inspectConfig)
              .setDeidentifyConfig(deidentifyConfig)
              .build();

      // Send the request and receive response from the service
      DeidentifyContentResponse response = dlp.deidentifyContent(request);

      // Print the results
      System.out.println(
          "Text after format-preserving encryption: " + response.getItem().getValue());
    }
  }
}

Node.js

To learn how to install and use the client library for Cloud DLP, see Cloud DLP client libraries.

// Imports the Google Cloud Data Loss Prevention library
const DLP = require('@google-cloud/dlp');

// Instantiates a client
const dlp = new DLP.DlpServiceClient();

// The project ID to run the API call under
// const projectId = 'my-project';

// The string to deidentify
// const string = 'My SSN is 372819127';

// The set of characters to replace sensitive ones with
// For more information, see https://cloud.google.com/dlp/docs/reference/rest/v2/organizations.deidentifyTemplates#ffxcommonnativealphabet
// const alphabet = 'ALPHA_NUMERIC';

// The name of the Cloud KMS key used to encrypt ('wrap') the AES-256 key
// const keyName = 'projects/YOUR_GCLOUD_PROJECT/locations/YOUR_LOCATION/keyRings/YOUR_KEYRING_NAME/cryptoKeys/YOUR_KEY_NAME';

// The encrypted ('wrapped') AES-256 key to use
// This key should be encrypted using the Cloud KMS key specified above
// const wrappedKey = 'YOUR_ENCRYPTED_AES_256_KEY'

// (Optional) The name of the surrogate custom info type to use
// Only necessary if you want to reverse the deidentification process
// Can be essentially any arbitrary string, as long as it doesn't appear
// in your dataset otherwise.
// const surrogateType = 'SOME_INFO_TYPE_DEID';

async function deidentifyWithFpe() {
  // Construct FPE config
  const cryptoReplaceFfxFpeConfig = {
    cryptoKey: {
      kmsWrapped: {
        wrappedKey: wrappedKey,
        cryptoKeyName: keyName,
      },
    },
    commonAlphabet: alphabet,
  };
  if (surrogateType) {
    cryptoReplaceFfxFpeConfig.surrogateInfoType = {
      name: surrogateType,
    };
  }

  // Construct deidentification request
  const item = {value: string};
  const request = {
    parent: `projects/${projectId}/locations/global`,
    deidentifyConfig: {
      infoTypeTransformations: {
        transformations: [
          {
            primitiveTransformation: {
              cryptoReplaceFfxFpeConfig: cryptoReplaceFfxFpeConfig,
            },
          },
        ],
      },
    },
    item: item,
  };

  // Run deidentification request
  const [response] = await dlp.deidentifyContent(request);
  const deidentifiedItem = response.item;
  console.log(deidentifiedItem.value);
}
deidentifyWithFpe();

PHP

To learn how to install and use the client library for Cloud DLP, see Cloud DLP client libraries.

/**
 * Deidentify a string using Format-Preserving Encryption (FPE).
 */
use Google\Cloud\Dlp\V2\CryptoReplaceFfxFpeConfig;
use Google\Cloud\Dlp\V2\CryptoReplaceFfxFpeConfig\FfxCommonNativeAlphabet;
use Google\Cloud\Dlp\V2\CryptoKey;
use Google\Cloud\Dlp\V2\DlpServiceClient;
use Google\Cloud\Dlp\V2\PrimitiveTransformation;
use Google\Cloud\Dlp\V2\KmsWrappedCryptoKey;
use Google\Cloud\Dlp\V2\InfoType;
use Google\Cloud\Dlp\V2\DeidentifyConfig;
use Google\Cloud\Dlp\V2\InfoTypeTransformations\InfoTypeTransformation;
use Google\Cloud\Dlp\V2\InfoTypeTransformations;
use Google\Cloud\Dlp\V2\ContentItem;

/** Uncomment and populate these variables in your code */
// $callingProjectId = 'The GCP Project ID to run the API call under';
// $string = 'The string to deidentify';
// $keyName = 'The name of the Cloud KMS key used to encrypt (wrap) the AES-256 key';
// $wrappedKey = 'The name of the Cloud KMS key use, encrypted with the KMS key in $keyName';
// $surrogateTypeName = ''; // (Optional) surrogate custom info type to enable reidentification

// Instantiate a client.
$dlp = new DlpServiceClient();

// The infoTypes of information to mask
$ssnInfoType = (new InfoType())
    ->setName('US_SOCIAL_SECURITY_NUMBER');
$infoTypes = [$ssnInfoType];

// Create the wrapped crypto key configuration object
$kmsWrappedCryptoKey = (new KmsWrappedCryptoKey())
    ->setWrappedKey(base64_decode($wrappedKey))
    ->setCryptoKeyName($keyName);

// The set of characters to replace sensitive ones with
// For more information, see https://cloud.google.com/dlp/docs/reference/rest/V2/organizations.deidentifyTemplates#ffxcommonnativealphabet
$commonAlphabet = FfxCommonNativeAlphabet::NUMERIC;

// Create the crypto key configuration object
$cryptoKey = (new CryptoKey())
    ->setKmsWrapped($kmsWrappedCryptoKey);

// Create the crypto FFX FPE configuration object
$cryptoReplaceFfxFpeConfig = (new CryptoReplaceFfxFpeConfig())
    ->setCryptoKey($cryptoKey)
    ->setCommonAlphabet($commonAlphabet);

if ($surrogateTypeName) {
    $surrogateType = (new InfoType())
        ->setName($surrogateTypeName);
    $cryptoReplaceFfxFpeConfig->setSurrogateInfoType($surrogateType);
}

// Create the information transform configuration objects
$primitiveTransformation = (new PrimitiveTransformation())
    ->setCryptoReplaceFfxFpeConfig($cryptoReplaceFfxFpeConfig);

$infoTypeTransformation = (new InfoTypeTransformation())
    ->setPrimitiveTransformation($primitiveTransformation)
    ->setInfoTypes($infoTypes);

$infoTypeTransformations = (new InfoTypeTransformations())
    ->setTransformations([$infoTypeTransformation]);

// Create the deidentification configuration object
$deidentifyConfig = (new DeidentifyConfig())
    ->setInfoTypeTransformations($infoTypeTransformations);

$content = (new ContentItem())
    ->setValue($string);

$parent = "projects/$callingProjectId/locations/global";

// Run request
$response = $dlp->deidentifyContent([
    'parent' => $parent,
    'deidentifyConfig' => $deidentifyConfig,
    'item' => $content
]);

// Print the results
$deidentifiedValue = $response->getItem()->getValue();
print($deidentifiedValue);

Python

To learn how to install and use the client library for Cloud DLP, see Cloud DLP client libraries.



def deidentify_with_fpe(
    project,
    input_str,
    info_types,
    alphabet=None,
    surrogate_type=None,
    key_name=None,
    wrapped_key=None,
):
    """Uses the Data Loss Prevention API to deidentify sensitive data in a
    string using Format Preserving Encryption (FPE).
    Args:
        project: The Google Cloud project id to use as a parent resource.
        input_str: The string to deidentify (will be treated as text).
        alphabet: The set of characters to replace sensitive ones with. For
            more information, see https://cloud.google.com/dlp/docs/reference/
            rest/v2beta2/organizations.deidentifyTemplates#ffxcommonnativealphabet
        surrogate_type: The name of the surrogate custom info type to use. Only
            necessary if you want to reverse the deidentification process. Can
            be essentially any arbitrary string, as long as it doesn't appear
            in your dataset otherwise.
        key_name: The name of the Cloud KMS key used to encrypt ('wrap') the
            AES-256 key. Example:
            key_name = 'projects/YOUR_GCLOUD_PROJECT/locations/YOUR_LOCATION/
            keyRings/YOUR_KEYRING_NAME/cryptoKeys/YOUR_KEY_NAME'
        wrapped_key: The encrypted ('wrapped') AES-256 key to use. This key
            should be encrypted using the Cloud KMS key specified by key_name.
    Returns:
        None; the response from the API is printed to the terminal.
    """
    # Import the client library
    import google.cloud.dlp

    # Instantiate a client
    dlp = google.cloud.dlp_v2.DlpServiceClient()

    # Convert the project id into a full resource id.
    parent = f"projects/{project}"

    # The wrapped key is base64-encoded, but the library expects a binary
    # string, so decode it here.
    import base64

    wrapped_key = base64.b64decode(wrapped_key)

    # Construct FPE configuration dictionary
    crypto_replace_ffx_fpe_config = {
        "crypto_key": {
            "kms_wrapped": {"wrapped_key": wrapped_key, "crypto_key_name": key_name}
        },
        "common_alphabet": alphabet,
    }

    # Add surrogate type
    if surrogate_type:
        crypto_replace_ffx_fpe_config["surrogate_info_type"] = {"name": surrogate_type}

    # Construct inspect configuration dictionary
    inspect_config = {"info_types": [{"name": info_type} for info_type in info_types]}

    # Construct deidentify configuration dictionary
    deidentify_config = {
        "info_type_transformations": {
            "transformations": [
                {
                    "primitive_transformation": {
                        "crypto_replace_ffx_fpe_config": crypto_replace_ffx_fpe_config
                    }
                }
            ]
        }
    }

    # Convert string to item
    item = {"value": input_str}

    # Call the API
    response = dlp.deidentify_content(
        request={
            "parent": parent,
            "deidentify_config": deidentify_config,
            "inspect_config": inspect_config,
            "item": item,
        }
    )

    # Print results
    print(response.item.value)

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