diff --git a/composer.json b/composer.json
index ced55f1..08992ab 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,8 @@
         }
     ],
     "require": {
-        "illuminate/support": "^6.0|^7.0"
+        "illuminate/support": "^6.0|^7.0",
+        "aws/aws-php-sns-message-validator": "^1.6"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/Concerns/HandlesSns.php b/src/Concerns/HandlesSns.php
index c46abee..f365e6a 100644
--- a/src/Concerns/HandlesSns.php
+++ b/src/Concerns/HandlesSns.php
@@ -2,29 +2,55 @@
 
 namespace Rennokki\LaravelSnsEvents\Concerns;
 
+use Aws\Sns\Message;
+use Aws\Sns\MessageValidator;
+use Exception;
 use Illuminate\Http\Request;
 
 trait HandlesSns
 {
     /**
-     * Get the payload content from the request.
+     * Get the SNS message as array.
      *
      * @param  \Illuminate\Http\Request  $request
-     * @return null|string
+     * @return \Aws\Sns\Message
      */
-    public function getRequestContent(Request $request)
+    public function getSnsMessage(Request $request)
     {
-        return $request->getContent() ?: file_get_contents('php://input');
+        try {
+            return Message::fromJsonString(
+                $request->getContent() ?: file_get_contents('php://input')
+            );
+        } catch (Exception $e) {
+            return new Message([]);
+        }
     }
 
     /**
-     * Get the JSON-decoded content.
+     * Check if the SNS message is valid.
      *
      * @param  \Illuminate\Http\Request  $request
-     * @return array
+     * @return bool
      */
-    public function getSnsMessage(Request $request): array
+    public function snsMessageIsValid(Request $request): bool
     {
-        return json_decode($this->getRequestContent($request), true);
+        try {
+            return $this->getMessageValidator($request)->isValid(
+                $this->getSnsMessage($request)
+            );
+        } catch (Exception $e) {
+            return false;
+        }
+    }
+
+    /**
+     * Get the message validator instance.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @return \Aws\Sns\MessageValidator
+     */
+    protected function getMessageValidator(Request $request)
+    {
+        return new MessageValidator;
     }
 }
diff --git a/src/Http/Controllers/SnsController.php b/src/Http/Controllers/SnsController.php
index 78baa97..65a8d3c 100644
--- a/src/Http/Controllers/SnsController.php
+++ b/src/Http/Controllers/SnsController.php
@@ -20,7 +20,11 @@ class SnsController extends Controller
      */
     public function handle(Request $request)
     {
-        $snsMessage = $this->getSnsMessage($request);
+        if (! $this->snsMessageIsValid($request)) {
+            return $this->okStatus();
+        }
+
+        $snsMessage = $this->getSnsMessage($request)->toArray();
 
         if (isset($snsMessage['Type'])) {
             if ($snsMessage['Type'] === 'SubscriptionConfirmation') {
@@ -46,7 +50,7 @@ public function handle(Request $request)
             }
         }
 
-        return response('OK', 200);
+        return $this->okStatus();
     }
 
     /**
@@ -121,4 +125,14 @@ protected function onSubscriptionConfirmation(array $snsMessage, Request $reques
     {
         //
     }
+
+    /**
+     * Get a 200 OK status.
+     *
+     * @return \Illuminate\Http\Response
+     */
+    protected function okStatus()
+    {
+        return response('OK', 200);
+    }
 }
diff --git a/tests/Controllers/CustomSnsController.php b/tests/Controllers/CustomSnsController.php
index bbb6ea4..bb306d9 100644
--- a/tests/Controllers/CustomSnsController.php
+++ b/tests/Controllers/CustomSnsController.php
@@ -2,6 +2,7 @@
 
 namespace Rennokki\LaravelSnsEvents\Tests\Controllers;
 
+use Aws\Sns\MessageValidator;
 use Illuminate\Http\Request;
 use Rennokki\LaravelSnsEvents\Http\Controllers\SnsController;
 use Rennokki\LaravelSnsEvents\Tests\Events\CustomSnsEvent;
@@ -86,4 +87,17 @@ protected function onSubscriptionConfirmation(array $snsMessage, Request $reques
     {
         mt_rand(0, 10000);
     }
+
+    /**
+     * Get the message validator instance.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @return \Aws\Sns\MessageValidator
+     */
+    protected function getMessageValidator(Request $request)
+    {
+        return new MessageValidator(function ($url) use ($request) {
+            return $request->certificate ?: $url;
+        });
+    }
 }
diff --git a/tests/Controllers/SnsController.php b/tests/Controllers/SnsController.php
new file mode 100644
index 0000000..5945f92
--- /dev/null
+++ b/tests/Controllers/SnsController.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Rennokki\LaravelSnsEvents\Tests\Controllers;
+
+use Aws\Sns\MessageValidator;
+use Illuminate\Http\Request;
+use Rennokki\LaravelSnsEvents\Http\Controllers\SnsController as BaseSnsController;
+
+class SnsController extends BaseSnsController
+{
+    /**
+     * Get the message validator instance.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @return \Aws\Sns\MessageValidator
+     */
+    protected function getMessageValidator(Request $request)
+    {
+        return new MessageValidator(function ($url) use ($request) {
+            return $request->certificate ?: $url;
+        });
+    }
+}
diff --git a/tests/EventTest.php b/tests/EventTest.php
index 21645a0..79f9f83 100644
--- a/tests/EventTest.php
+++ b/tests/EventTest.php
@@ -14,8 +14,22 @@ public function test_no_event_triggering_on_bad_request()
     {
         Event::fake();
 
-        $this
-            ->json('GET', route('sns'))
+        $this->json('GET', route('sns'))
+            ->assertSee('OK');
+
+        Event::assertNotDispatched(SnsNotification::class);
+        Event::assertNotDispatched(SnsSubscriptionConfirmation::class);
+
+        $this->json('GET', route('sns', ['certificate' => static::$certificate]))
+            ->assertSee('OK');
+
+        Event::assertNotDispatched(SnsNotification::class);
+        Event::assertNotDispatched(SnsSubscriptionConfirmation::class);
+
+        $payload = $this->getSubscriptionConfirmationPayload();
+
+        $this->withHeaders($this->getHeadersForMessage($payload))
+            ->json('GET', route('sns', ['certificate' => static::$certificate]))
             ->assertSee('OK');
 
         Event::assertNotDispatched(SnsNotification::class);
@@ -26,12 +40,13 @@ public function test_subscription_confirmation()
     {
         Event::fake();
 
-        $this
-            ->withHeaders([
-                'x-test-header' => 1,
-            ])
-            ->json('POST', route('sns'), $this->getSubscriptionConfirmationPayload())
-            ->assertSee('OK');
+        $payload = $this->getSubscriptionConfirmationPayload();
+
+        $this->withHeaders(array_merge($this->getHeadersForMessage($payload), [
+            'x-test-header' => 1,
+        ]))
+        ->json('POST', route('sns', ['certificate' => static::$certificate]), $payload)
+        ->assertSee('OK');
 
         Event::assertNotDispatched(SnsNotification::class);
 
@@ -48,17 +63,16 @@ public function test_notification_confirmation()
     {
         Event::fake();
 
-        $payload = json_encode([
+        $payload = $this->getNotificationPayload([
             'test' => 1,
             'sns' => true,
         ]);
 
-        $this
-            ->withHeaders([
-                'x-test-header' => 1,
-            ])
-            ->json('POST', route('sns'), $this->getNotificationPayload($payload))
-            ->assertSee('OK');
+        $this->withHeaders(array_merge($this->getHeadersForMessage($payload), [
+            'x-test-header' => 1,
+        ]))
+        ->json('POST', route('sns', ['certificate' => static::$certificate]), $payload)
+        ->assertSee('OK');
 
         Event::assertNotDispatched(SnsSubscriptionConfirmation::class);
 
@@ -82,12 +96,13 @@ public function test_custom_controller_confirmation()
     {
         Event::fake();
 
-        $this
-            ->withHeaders([
-                'x-test-header' => 1,
-            ])
-            ->json('POST', route('custom-sns', ['test' => 'some-string']), $this->getSubscriptionConfirmationPayload())
-            ->assertSee('OK');
+        $payload = $this->getSubscriptionConfirmationPayload();
+
+        $this->withHeaders(array_merge($this->getHeadersForMessage($payload), [
+            'x-test-header' => 1,
+        ]))
+        ->json('POST', route('custom-sns', ['test' => 'some-string', 'certificate' => static::$certificate]), $payload)
+        ->assertSee('OK');
 
         Event::assertNotDispatched(CustomSnsEvent::class);
 
@@ -108,17 +123,16 @@ public function test_custom_controller_notification()
     {
         Event::fake();
 
-        $payload = json_encode([
+        $payload = $this->getNotificationPayload([
             'test' => 1,
             'sns' => true,
         ]);
 
-        $this
-            ->withHeaders([
-                'x-test-header' => 1,
-            ])
-            ->json('POST', route('custom-sns', ['test' => 'some-string']), $this->getNotificationPayload($payload))
-            ->assertSee('OK');
+        $this->withHeaders(array_merge($this->getHeadersForMessage($payload), [
+            'x-test-header' => 1,
+        ]))
+        ->json('POST', route('custom-sns', ['test' => 'some-string', 'certificate' => static::$certificate]), $payload)
+        ->assertSee('OK');
 
         Event::assertNotDispatched(CustomSubscriptionConfirmation::class);
 
diff --git a/tests/TestCase.php b/tests/TestCase.php
index c42590b..2c1f840 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -2,10 +2,55 @@
 
 namespace Rennokki\LaravelSnsEvents\Tests;
 
+use Aws\Sns\Message;
+use Aws\Sns\MessageValidator;
 use Orchestra\Testbench\TestCase as Orchestra;
 
 class TestCase extends Orchestra
 {
+    /**
+     * Get the private key to sign the request.
+     *
+     * @var string
+     */
+    protected static $privateKey;
+
+    /**
+     * The certificate to sign the request.
+     *
+     * @var string
+     */
+    protected static $certificate;
+
+    /**
+     * @var string
+     */
+    const VALID_CERT_URL = 'https://sns.us-west-2.amazonaws.com/bar.pem';
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function setUpBeforeClass(): void
+    {
+        self::$privateKey = openssl_pkey_new();
+
+        $csr = openssl_csr_new([], self::$privateKey);
+
+        $x509 = openssl_csr_sign($csr, null, self::$privateKey, 1);
+
+        openssl_x509_export($x509, self::$certificate);
+
+        openssl_x509_free($x509);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function tearDownAfterClass(): void
+    {
+        openssl_pkey_free(self::$privateKey);
+    }
+
     /**
      * Get package providers.
      *
@@ -22,57 +67,103 @@ protected function getPackageProviders($app)
     }
 
     /**
-     * Define environment setup.
-     *
-     * @param  \Illuminate\Foundation\Application   $app
-     *
-     * @return void
+     * {@inheritdoc}
      */
     protected function getEnvironmentSetUp($app)
     {
         $app['config']->set('app.key', '6rE9Nz59bGRbeMATftriyQjrpF7DcOQm');
     }
 
+    /**
+     * Get the signature for the message.
+     *
+     * @param  string  $stringToSign
+     * @return string
+     */
+    protected function getSignature($stringToSign)
+    {
+        openssl_sign($stringToSign, $signature, self::$privateKey);
+
+        return base64_encode($signature);
+    }
+
     /**
      * Get an example subscription payload for testing.
      *
+     * @param  array  $custom
      * @return array
      */
-    protected function getSubscriptionConfirmationPayload(): array
+    protected function getSubscriptionConfirmationPayload(array $custom = []): array
     {
-        return [
+        $validator = new MessageValidator;
+
+        $message = array_merge([
             'Type' => 'SubscriptionConfirmation',
             'MessageId' => '165545c9-2a5c-472c-8df2-7ff2be2b3b1b',
             'Token' => '2336412f37...',
             'TopicArn' => 'arn:aws:sns:us-west-2:123456789012:MyTopic',
             'Message' => 'You have chosen to subscribe to the topic arn:aws:sns:us-west-2:123456789012:MyTopic.\nTo confirm the subscription, visit the SubscribeURL included in this message.',
             'SubscribeURL' => 'https://example.com',
-            'Timestamp' => '2012-04-26T20:45:04.751Z',
+            'Timestamp' => now()->toDateTimeString(),
             'SignatureVersion' => '1',
-            'Signature' => 'EXAMPLEpH+DcEwjAPg8O9mY8dReBSwksfg2S7WKQcikcNKWLQjwu6A4VbeS0QHVCkhRS7fUQvi2egU3N858fiTDN6bkkOxYDVrY0Ad8L10Hs3zH81mtnPk5uvvolIC1CXGu43obcgFxeL3khZl8IKvO61GWB6jI9b5+gLPoBc1Q=',
-            'SigningCertURL' => 'https://sns.us-west-2.amazonaws.com/SimpleNotificationService-f3ecfb7224c7233fe7bb5f59f96de52f.pem',
-        ];
+            'Signature' => true,
+            'SigningCertURL' => self::VALID_CERT_URL,
+        ], $custom);
+
+        $message['Signature'] = $this->getSignature(
+            $validator->getStringToSign(new Message($message))
+        );
+
+        return $message;
     }
 
     /**
      * Get an example notification payload for testing.
      *
      * @param  string  $payload
+     * @param  array  $custom
      * @return array
      */
-    protected function getNotificationPayload($payload = ''): array
+    protected function getNotificationPayload($payload = '', array $custom = []): array
     {
-        return [
+        $validator = new MessageValidator;
+
+        $payload = json_encode($payload);
+
+        $message = array_merge([
             'Type' => 'Notification',
             'MessageId' => '22b80b92-fdea-4c2c-8f9d-bdfb0c7bf324',
             'TopicArn' => 'arn:aws:sns:us-west-2:123456789012:MyTopic',
             'Subject' => 'My First Message',
             'Message' => "{$payload}",
-            'Timestamp' => '2012-05-02T00:54:06.655Z',
+            'Timestamp' => now()->toDateTimeString(),
             'SignatureVersion' => '1',
-            'Signature' => 'EXAMPLEw6JRN...',
-            'SigningCertURL' => 'https://sns.us-west-2.amazonaws.com/SimpleNotificationService-f3ecfb7224c7233fe7bb5f59f96de52f.pem',
+            'Token' => '2336412f37...',
+            'Signature' => true,
+            'SigningCertURL' => self::VALID_CERT_URL,
             'UnsubscribeURL' => 'https://sns.us-west-2.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:us-west-2:123456789012:MyTopic:c9135db0-26c4-47ec-8998-413945fb5a96',
+        ], $custom);
+
+        $message['Signature'] = $this->getSignature(
+            $validator->getStringToSign(new Message($message))
+        );
+
+        return $message;
+    }
+
+    /**
+     * Get the right headers for a SNS message.
+     *
+     * @param  array  $message
+     * @return array
+     */
+    protected function getHeadersForMessage(array $message): array
+    {
+        return [
+            'X-AMZ-SNS-MESSAGE-TYPE' => $message['Type'],
+            'X-AMZ-SNS-MESSAGE-ID' => $message['MessageId'],
+            'X-AMZ-SNS-TOPIC-ARN' => $message['TopicArn'],
+            'X-AMZ-SNS-SUBSCRIPTION-ARN' => "{$message['TopicArn']}:c9135db0-26c4-47ec-8998-413945fb5a96",
         ];
     }
 }
diff --git a/tests/routes/web.php b/tests/routes/web.php
index 8d8fc6c..24aa3e9 100644
--- a/tests/routes/web.php
+++ b/tests/routes/web.php
@@ -2,7 +2,7 @@
 
 use Illuminate\Support\Facades\Route;
 
-Route::any('/sns', 'Rennokki\LaravelSnsEvents\Http\Controllers\SnsController@handle')
+Route::any('/sns', 'Rennokki\LaravelSnsEvents\Tests\Controllers\SnsController@handle')
     ->name('sns');
 
 Route::any('/sns-custom', 'Rennokki\LaravelSnsEvents\Tests\Controllers\CustomSnsController@handle')