diff --git a/src/Activities/VerificationHandler.php b/src/Activities/VerificationHandler.php
new file mode 100644
index 0000000..6cea379
--- /dev/null
+++ b/src/Activities/VerificationHandler.php
@@ -0,0 +1,46 @@
+<?php
+namespace ActivityPub\Activities;
+
+use ActivityPub\Activities\InboxActivityEvent;
+use ActivityPub\Activities\OutboxActivityEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
+
+class VerificationHandler implements EventSubscriberInterface
+{
+    public static function getSubscribedEvents()
+    {
+        return array(
+            InboxActivityEvent::NAME => 'verifyInboxActivity',
+            OutboxActivityEvent::NAME => 'verifyOutboxActivity',
+        );
+    }
+
+    public function verifyInboxActivity( InboxActivityEvent $event )
+    {
+        $activity = $event->getActivity();
+        $this->requireFields( $activity, array( 'type', 'id', 'actor' ) );
+    }
+
+    public function verifyOutboxActivity( OutboxActivityEvent $event )
+    {
+        $activity = $event->getActivity();
+        $this->requireFields( $activity, array( 'type' ) );
+    }
+
+    private function requireFields( array $activity, array $fields )
+    {
+        $missing = array();
+        foreach ( $fields as $field ) {
+            if ( ! array_key_exists( $field, $activity ) ) {
+                $missing[] = $field;
+            }
+        }
+        if ( count( $missing ) > 0 ) {
+            throw new BadRequestHttpException(
+                "Missing activity fields: " . implode( ',', $missing )
+            );
+        }
+    }
+}
+?>
diff --git a/test/Activities/VerificationHandlerTest.php b/test/Activities/VerificationHandlerTest.php
new file mode 100644
index 0000000..ad625c2
--- /dev/null
+++ b/test/Activities/VerificationHandlerTest.php
@@ -0,0 +1,117 @@
+<?php
+namespace ActivityPub\Test\Activities;
+
+use ActivityPub\Activities\InboxActivityEvent;
+use ActivityPub\Activities\OutboxActivityEvent;
+use ActivityPub\Activities\VerificationHandler;
+use ActivityPub\Test\TestUtils\TestActivityPubObject;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
+
+class VerificationHandlerTest extends TestCase
+{
+    /**
+     * @var EventDispatcher
+     */
+    private $eventDispatcher;
+    
+    public function setUp()
+    {
+        $this->eventDispatcher = new EventDispatcher();
+        $verificationHandler = new VerificationHandler();
+        $this->eventDispatcher->addSubscriber( $verificationHandler );
+    }
+    public function testVerificationHandler()
+    {
+        $testCases = array(
+            array(
+                'id' => 'inboxRequiredFields',
+                'activity' => array(),
+                'eventName' => InboxActivityEvent::NAME,
+                'event' => new InboxActivityEvent(
+                    array(),
+                    TestActivityPubObject::fromArray( array(
+                        'id' => 'https://notexample.com/actor/1',
+                        'type' => 'Person',
+                    ) ),
+                    Request::create( 'https://example.com' )
+                ),
+                'expectedException' => BadRequestHttpException::class,
+                'expectedExceptionMessage' => 'Missing activity fields: type,id,actor',
+            ),
+            array(
+                'id' => 'outboxRequiredFields',
+                'activity' => array(),
+                'eventName' => OutboxActivityEvent::NAME,
+                'event' => new OutboxActivityEvent(
+                    array(),
+                    TestActivityPubObject::fromArray( array(
+                        'id' => 'https://example.com/actor/1',
+                        'type' => 'Person',
+                    ) ),
+                    Request::create( 'https://example.com' )
+                ),
+                'expectedException' => BadRequestHttpException::class,
+                'expectedExceptionMessage' => 'Missing activity fields: type',
+            ),
+            array(
+                'id' => 'inboxPassesValidActivity',
+                'activity' => array(
+                    'id' => 'https://notexample.com/activity/1',
+                    'type' => 'Create',
+                    'actor' => 'https://notexample.com/actor/1',
+                ),
+                'eventName' => InboxActivityEvent::NAME,
+                'event' => new InboxActivityEvent(
+                    array(
+                        'id' => 'https://notexample.com/activity/1',
+                        'type' => 'Create',
+                        'actor' => 'https://notexample.com/actor/1',
+                    ),
+                    TestActivityPubObject::fromArray( array(
+                        'id' => 'https://notexample.com/actor/1',
+                        'type' => 'Person',
+                    ) ),
+                    Request::create( 'https://example.com' )
+                ),
+            ),
+            array(
+                'id' => 'outboxPassesValidActivity',
+                'activity' => array(
+                    'type' => 'Create',
+                ),
+                'eventName' => OutboxActivityEvent::NAME,
+                'event' => new OutboxActivityEvent(
+                    array(
+                        'type' => 'Create',
+                    ),
+                    TestActivityPubObject::fromArray( array(
+                        'id' => 'https://example.com/actor/1',
+                        'type' => 'Person',
+                    ) ),
+                    Request::create( 'https://example.com' )
+                ),
+            ),
+        );
+        foreach ( $testCases as $testCase ) {
+            $activity = $testCase['activity'];
+            $event = $testCase['event'];
+            if ( array_key_exists( 'expectedException', $testCase ) ) {
+                $this->expectException(
+                    $testCase['expectedException'],
+                    "Error on test $testCase[id]"
+                );
+            }
+            if ( array_key_exists( 'expectedExceptionMessage', $testCase ) ) {
+                $this->expectExceptionMessage(
+                    $testCase['expectedExceptionMessage'],
+                    "Error on test $testCase[id]"
+                );
+            }
+            $this->eventDispatcher->dispatch( $testCase['eventName'], $event );
+        }
+    }
+}
+?>