diff --git a/src/Module/Objects.php b/src/Module/Objects.php
index 8080289f15..e032654869 100644
--- a/src/Module/Objects.php
+++ b/src/Module/Objects.php
@@ -25,9 +25,11 @@ use Friendica\BaseModule;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Contact;
 use Friendica\Model\Item;
 use Friendica\Network\HTTPException;
 use Friendica\Protocol\ActivityPub;
+use Friendica\Util\HTTPSignature;
 use Friendica\Util\Network;
 
 /**
@@ -45,17 +47,27 @@ class Objects extends BaseModule
 			DI::baseUrl()->redirect(str_replace('objects/', 'display/', DI::args()->getQueryString()));
 		}
 
-		/// @todo Add Authentication to enable fetching of non public content
-		// $requester = HTTPSignature::getSigner('', $_SERVER);
+		$item = Item::selectFirst(['id', 'uid', 'origin', 'author-link', 'changed', 'private', 'psid'],
+			['guid' => $parameters['guid']], ['order' => ['origin' => true]]);
+
+		$validated = false;
+		$requester = HTTPSignature::getSigner('', $_SERVER);
+		if (!empty($requester) && $item['origin']) {
+			$requester_id = Contact::getIdForURL($requester, $item['uid']);
+			if (!empty($requester_id)) {
+				$permissionSets = DI::permissionSet()->selectByContactId($requester_id, $item['uid']);
+				if (!empty($permissionSets)) {
+					$psid = array_merge($permissionSets->column('id'),
+						[DI::permissionSet()->getIdFromACL($item['uid'], '', '', '', '')]);
+					$validated = in_array($item['psid'], $psid);
+				}
+			}
+		}
+
+		if (!$validated && !in_array($item['private'], [Item::PUBLIC, Item::UNLISTED])) {
+			unset($item);
+		}
 
-		$item = Item::selectFirst(
-			['id', 'origin', 'author-link', 'changed'],
-			[
-				'guid' => $parameters['guid'],
-				'private' => [Item::PUBLIC, Item::UNLISTED]
-			],
-			['order' => ['origin' => true]]
-		);
 		// Valid items are original post or posted from this node (including in the case of a forum)
 		if (!DBA::isResult($item) || !$item['origin'] && (parse_url($item['author-link'], PHP_URL_HOST) != parse_url(DI::baseUrl()->get(), PHP_URL_HOST))) {
 			throw new HTTPException\NotFoundException();
diff --git a/src/Module/Outbox.php b/src/Module/Outbox.php
index 265c130b18..3a822cc6e5 100644
--- a/src/Module/Outbox.php
+++ b/src/Module/Outbox.php
@@ -22,10 +22,10 @@
 namespace Friendica\Module;
 
 use Friendica\BaseModule;
-use Friendica\Core\System;
 use Friendica\DI;
 use Friendica\Model\User;
 use Friendica\Protocol\ActivityPub;
+use Friendica\Util\HTTPSignature;
 
 /**
  * ActivityPub Outbox
@@ -48,11 +48,8 @@ class Outbox extends BaseModule
 
 		$page = $_REQUEST['page'] ?? null;
 
-		/// @todo Add Authentication to enable fetching of non public content
-		// $requester = HTTPSignature::getSigner('', $_SERVER);
-
-		$outbox = ActivityPub\Transmitter::getOutbox($owner, $page);
-
+		$requester = HTTPSignature::getSigner('', $_SERVER);
+		$outbox = ActivityPub\Transmitter::getOutbox($owner, $page, $requester);
 		header('Content-Type: application/activity+json');
 		echo json_encode($outbox);
 		exit();
diff --git a/src/Protocol/ActivityPub/Transmitter.php b/src/Protocol/ActivityPub/Transmitter.php
index 2abc883078..c798e619ec 100644
--- a/src/Protocol/ActivityPub/Transmitter.php
+++ b/src/Protocol/ActivityPub/Transmitter.php
@@ -141,20 +141,37 @@ class Transmitter
 	/**
 	 * Public posts for the given owner
 	 *
-	 * @param array   $owner Owner array
-	 * @param integer $page  Page numbe
+	 * @param array   $owner     Owner array
+	 * @param integer $page      Page number
+	 * @param string  $requester URL of requesting account
 	 *
 	 * @return array of posts
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function getOutbox($owner, $page = null)
+	public static function getOutbox($owner, $page = null, $requester = '')
 	{
 		$public_contact = Contact::getIdForURL($owner['url']);
+		$condition = ['uid' => 0, 'contact-id' => $public_contact,
+			'private' => [Item::PUBLIC, Item::UNLISTED]];
+
+		if (!empty($requester)) {
+			$requester_id = Contact::getIdForURL($requester, $owner['uid']);
+			if (!empty($requester_id)) {
+				$permissionSets = DI::permissionSet()->selectByContactId($requester_id, $owner['uid']);
+				if (!empty($permissionSets)) {
+					$condition = ['uid' => $owner['uid'], 'origin' => true,
+						'psid' => array_merge($permissionSets->column('id'),
+							[DI::permissionSet()->getIdFromACL($owner['uid'], '', '', '', '')])];
+				}
+			}
+		}
+
+		$condition = array_merge($condition,
+			['author-id' => $public_contact,
+			'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT],
+			'deleted' => false, 'visible' => true, 'moderated' => false]);
 
-		$condition = ['uid' => 0, 'contact-id' => $public_contact, 'author-id' => $public_contact,
-			'private' => [Item::PUBLIC, Item::UNLISTED], 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT],
-			'deleted' => false, 'visible' => true, 'moderated' => false];
 		$count = DBA::count('item', $condition);
 
 		$data = ['@context' => ActivityPub::CONTEXT];
diff --git a/src/Util/HTTPSignature.php b/src/Util/HTTPSignature.php
index 5165f600fc..cdee48bfc0 100644
--- a/src/Util/HTTPSignature.php
+++ b/src/Util/HTTPSignature.php
@@ -484,7 +484,7 @@ class HTTPSignature
 		}
 
 		$headers = [];
-		$headers['(request-target)'] = strtolower($http_headers['REQUEST_METHOD']) . ' ' . $http_headers['REQUEST_URI'];
+		$headers['(request-target)'] = strtolower($http_headers['REQUEST_METHOD']) . ' ' . parse_url($http_headers['REQUEST_URI'], PHP_URL_PATH);
 
 		// First take every header
 		foreach ($http_headers as $k => $v) {