diff --git a/SecretManager/metadata/V1/Resources.php b/SecretManager/metadata/V1/Resources.php
index f77eb3e4451..357721f4da3 100644
Binary files a/SecretManager/metadata/V1/Resources.php and b/SecretManager/metadata/V1/Resources.php differ
diff --git a/SecretManager/src/V1/SecretPayload.php b/SecretManager/src/V1/SecretPayload.php
index 97c693f42e2..54e2d71de85 100644
--- a/SecretManager/src/V1/SecretPayload.php
+++ b/SecretManager/src/V1/SecretPayload.php
@@ -22,6 +22,20 @@ class SecretPayload extends \Google\Protobuf\Internal\Message
      * Generated from protobuf field <code>bytes data = 1;</code>
      */
     private $data = '';
+    /**
+     * Optional. If specified, [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] will verify the integrity of the
+     * received [data][google.cloud.secretmanager.v1.SecretPayload.data] on [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion] calls using
+     * the crc32c checksum and store it to include in future
+     * [SecretManagerService.AccessSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AccessSecretVersion] responses. If a checksum is
+     * not provided in the [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion] request, the
+     * [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] will generate and store one for you.
+     * The CRC32C value is encoded as a Int64 for compatibility, and can be
+     * safely downconverted to uint32 in languages that support this type.
+     * https://cloud.google.com/apis/design/design_patterns#integer_types
+     *
+     * Generated from protobuf field <code>optional int64 data_crc32c = 2 [(.google.api.field_behavior) = OPTIONAL];</code>
+     */
+    private $data_crc32c = null;
 
     /**
      * Constructor.
@@ -31,6 +45,16 @@ class SecretPayload extends \Google\Protobuf\Internal\Message
      *
      *     @type string $data
      *           The secret data. Must be no larger than 64KiB.
+     *     @type int|string $data_crc32c
+     *           Optional. If specified, [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] will verify the integrity of the
+     *           received [data][google.cloud.secretmanager.v1.SecretPayload.data] on [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion] calls using
+     *           the crc32c checksum and store it to include in future
+     *           [SecretManagerService.AccessSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AccessSecretVersion] responses. If a checksum is
+     *           not provided in the [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion] request, the
+     *           [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] will generate and store one for you.
+     *           The CRC32C value is encoded as a Int64 for compatibility, and can be
+     *           safely downconverted to uint32 in languages that support this type.
+     *           https://cloud.google.com/apis/design/design_patterns#integer_types
      * }
      */
     public function __construct($data = NULL) {
@@ -64,5 +88,57 @@ public function setData($var)
         return $this;
     }
 
+    /**
+     * Optional. If specified, [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] will verify the integrity of the
+     * received [data][google.cloud.secretmanager.v1.SecretPayload.data] on [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion] calls using
+     * the crc32c checksum and store it to include in future
+     * [SecretManagerService.AccessSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AccessSecretVersion] responses. If a checksum is
+     * not provided in the [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion] request, the
+     * [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] will generate and store one for you.
+     * The CRC32C value is encoded as a Int64 for compatibility, and can be
+     * safely downconverted to uint32 in languages that support this type.
+     * https://cloud.google.com/apis/design/design_patterns#integer_types
+     *
+     * Generated from protobuf field <code>optional int64 data_crc32c = 2 [(.google.api.field_behavior) = OPTIONAL];</code>
+     * @return int|string
+     */
+    public function getDataCrc32C()
+    {
+        return isset($this->data_crc32c) ? $this->data_crc32c : 0;
+    }
+
+    public function hasDataCrc32C()
+    {
+        return isset($this->data_crc32c);
+    }
+
+    public function clearDataCrc32C()
+    {
+        unset($this->data_crc32c);
+    }
+
+    /**
+     * Optional. If specified, [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] will verify the integrity of the
+     * received [data][google.cloud.secretmanager.v1.SecretPayload.data] on [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion] calls using
+     * the crc32c checksum and store it to include in future
+     * [SecretManagerService.AccessSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AccessSecretVersion] responses. If a checksum is
+     * not provided in the [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion] request, the
+     * [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] will generate and store one for you.
+     * The CRC32C value is encoded as a Int64 for compatibility, and can be
+     * safely downconverted to uint32 in languages that support this type.
+     * https://cloud.google.com/apis/design/design_patterns#integer_types
+     *
+     * Generated from protobuf field <code>optional int64 data_crc32c = 2 [(.google.api.field_behavior) = OPTIONAL];</code>
+     * @param int|string $var
+     * @return $this
+     */
+    public function setDataCrc32C($var)
+    {
+        GPBUtil::checkInt64($var);
+        $this->data_crc32c = $var;
+
+        return $this;
+    }
+
 }
 
diff --git a/SecretManager/src/V1/SecretVersion.php b/SecretManager/src/V1/SecretVersion.php
index 49abe0769fb..8737c806eac 100644
--- a/SecretManager/src/V1/SecretVersion.php
+++ b/SecretManager/src/V1/SecretVersion.php
@@ -56,6 +56,14 @@ class SecretVersion extends \Google\Protobuf\Internal\Message
      * Generated from protobuf field <code>string etag = 6 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>
      */
     private $etag = '';
+    /**
+     * Output only. True if payload checksum specified in [SecretPayload][google.cloud.secretmanager.v1.SecretPayload] object has been
+     * received by [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] on
+     * [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion].
+     *
+     * Generated from protobuf field <code>bool client_specified_payload_checksum = 7 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>
+     */
+    private $client_specified_payload_checksum = false;
 
     /**
      * Constructor.
@@ -80,6 +88,10 @@ class SecretVersion extends \Google\Protobuf\Internal\Message
      *           The replication status of the [SecretVersion][google.cloud.secretmanager.v1.SecretVersion].
      *     @type string $etag
      *           Output only. Etag of the currently stored [SecretVersion][google.cloud.secretmanager.v1.SecretVersion].
+     *     @type bool $client_specified_payload_checksum
+     *           Output only. True if payload checksum specified in [SecretPayload][google.cloud.secretmanager.v1.SecretPayload] object has been
+     *           received by [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] on
+     *           [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion].
      * }
      */
     public function __construct($data = NULL) {
@@ -283,5 +295,35 @@ public function setEtag($var)
         return $this;
     }
 
+    /**
+     * Output only. True if payload checksum specified in [SecretPayload][google.cloud.secretmanager.v1.SecretPayload] object has been
+     * received by [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] on
+     * [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion].
+     *
+     * Generated from protobuf field <code>bool client_specified_payload_checksum = 7 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>
+     * @return bool
+     */
+    public function getClientSpecifiedPayloadChecksum()
+    {
+        return $this->client_specified_payload_checksum;
+    }
+
+    /**
+     * Output only. True if payload checksum specified in [SecretPayload][google.cloud.secretmanager.v1.SecretPayload] object has been
+     * received by [SecretManagerService][google.cloud.secretmanager.v1.SecretManagerService] on
+     * [SecretManagerService.AddSecretVersion][google.cloud.secretmanager.v1.SecretManagerService.AddSecretVersion].
+     *
+     * Generated from protobuf field <code>bool client_specified_payload_checksum = 7 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>
+     * @param bool $var
+     * @return $this
+     */
+    public function setClientSpecifiedPayloadChecksum($var)
+    {
+        GPBUtil::checkBool($var);
+        $this->client_specified_payload_checksum = $var;
+
+        return $this;
+    }
+
 }
 
diff --git a/SecretManager/tests/Unit/V1/SecretManagerServiceClientTest.php b/SecretManager/tests/Unit/V1/SecretManagerServiceClientTest.php
index d4f0dea217f..6f7e36baa59 100644
--- a/SecretManager/tests/Unit/V1/SecretManagerServiceClientTest.php
+++ b/SecretManager/tests/Unit/V1/SecretManagerServiceClientTest.php
@@ -154,9 +154,11 @@ public function addSecretVersionTest()
         // Mock response
         $name = 'name3373707';
         $etag = 'etag3123477';
+        $clientSpecifiedPayloadChecksum = false;
         $expectedResponse = new SecretVersion();
         $expectedResponse->setName($name);
         $expectedResponse->setEtag($etag);
+        $expectedResponse->setClientSpecifiedPayloadChecksum($clientSpecifiedPayloadChecksum);
         $transport->addResponse($expectedResponse);
         // Mock request
         $formattedParent = $client->secretName('[PROJECT]', '[SECRET]');
@@ -363,9 +365,11 @@ public function destroySecretVersionTest()
         // Mock response
         $name2 = 'name2-1052831874';
         $etag2 = 'etag2-1293302904';
+        $clientSpecifiedPayloadChecksum = false;
         $expectedResponse = new SecretVersion();
         $expectedResponse->setName($name2);
         $expectedResponse->setEtag($etag2);
+        $expectedResponse->setClientSpecifiedPayloadChecksum($clientSpecifiedPayloadChecksum);
         $transport->addResponse($expectedResponse);
         // Mock request
         $formattedName = $client->secretVersionName('[PROJECT]', '[SECRET]', '[SECRET_VERSION]');
@@ -429,9 +433,11 @@ public function disableSecretVersionTest()
         // Mock response
         $name2 = 'name2-1052831874';
         $etag2 = 'etag2-1293302904';
+        $clientSpecifiedPayloadChecksum = false;
         $expectedResponse = new SecretVersion();
         $expectedResponse->setName($name2);
         $expectedResponse->setEtag($etag2);
+        $expectedResponse->setClientSpecifiedPayloadChecksum($clientSpecifiedPayloadChecksum);
         $transport->addResponse($expectedResponse);
         // Mock request
         $formattedName = $client->secretVersionName('[PROJECT]', '[SECRET]', '[SECRET_VERSION]');
@@ -495,9 +501,11 @@ public function enableSecretVersionTest()
         // Mock response
         $name2 = 'name2-1052831874';
         $etag2 = 'etag2-1293302904';
+        $clientSpecifiedPayloadChecksum = false;
         $expectedResponse = new SecretVersion();
         $expectedResponse->setName($name2);
         $expectedResponse->setEtag($etag2);
+        $expectedResponse->setClientSpecifiedPayloadChecksum($clientSpecifiedPayloadChecksum);
         $transport->addResponse($expectedResponse);
         // Mock request
         $formattedName = $client->secretVersionName('[PROJECT]', '[SECRET]', '[SECRET_VERSION]');
@@ -693,9 +701,11 @@ public function getSecretVersionTest()
         // Mock response
         $name2 = 'name2-1052831874';
         $etag = 'etag3123477';
+        $clientSpecifiedPayloadChecksum = false;
         $expectedResponse = new SecretVersion();
         $expectedResponse->setName($name2);
         $expectedResponse->setEtag($etag);
+        $expectedResponse->setClientSpecifiedPayloadChecksum($clientSpecifiedPayloadChecksum);
         $transport->addResponse($expectedResponse);
         // Mock request
         $formattedName = $client->secretVersionName('[PROJECT]', '[SECRET]', '[SECRET_VERSION]');