diff --git a/config.ini b/config.ini
index 5ade62e..9e2e5c0 100644
--- a/config.ini
+++ b/config.ini
@@ -21,7 +21,5 @@ username = 'federatoradmin'
 password = '*change*me*as*well'
 
 [keys]
-headerSenderName = 'contentnation'
-contentnationPublicKeyPath = '../contentnation.pub'
 federatorPrivateKeyPath = '../federator.key'
 federatorPublicKeyPath = '../federator.pub'
\ No newline at end of file
diff --git a/contentnation.ini b/contentnation.ini
index 6f447fd..9f56c3f 100644
--- a/contentnation.ini
+++ b/contentnation.ini
@@ -3,4 +3,8 @@ service-uri = http://local.contentnation.net
 
 [userdata]
 path = '/home/net/contentnation/userdata/htdocs/' // need to download local copy of image and put img-path here
-url = 'https://userdata.contentnation.net'
\ No newline at end of file
+url = 'https://userdata.contentnation.net'
+
+[keys]
+headerSenderName = 'contentnation'
+publicKeyPath = '../contentnation.pub'
\ No newline at end of file
diff --git a/php/federator/api.php b/php/federator/api.php
index 92566c9..6f901a1 100644
--- a/php/federator/api.php
+++ b/php/federator/api.php
@@ -107,6 +107,9 @@ class Api extends Main
                     case 'dummy':
                         $handler = new Api\V1\Dummy($this);
                         break;
+                    case 'newcontent':
+                        $handler = new Api\V1\NewContent($this);
+                        break;
                 }
                 break;
         }
@@ -201,6 +204,15 @@ class Api extends Main
      */
     public function checkSignature($headers)
     {
+        if (isset($headers['X-Sender'])) {
+            try {
+                return $this->connector->checkSignature($headers);
+            } catch (Exceptions\PermissionDenied $e) {
+                http_response_code(500);
+                throw $e;
+            }
+        }
+
         $signatureHeader = $headers['Signature'] ?? null;
 
         if (!isset($signatureHeader)) {
@@ -213,12 +225,11 @@ class Api extends Main
 
         $signature = base64_decode($signatureParts['signature']);
         $signedHeaders = explode(' ', $signatureParts['headers']);
-        if (isset($headers['X-Sender']) && $headers['X-Sender'] === $this->config['keys']['headerSenderName']) {
-            $pKeyPath = $_SERVER['DOCUMENT_ROOT'] . $this->config['keys']['contentnationPublicKeyPath'];
-            $publicKeyPem = file_get_contents($pKeyPath);
-        } else {
-            $keyId = $signatureParts['keyId'];
+        $keyId = $signatureParts['keyId'];
 
+        $publicKeyPem = $this->cache->getPublicKey($keyId);
+
+        if (!isset($publicKeyPem) || $publicKeyPem === false) {
             // Fetch public key from `keyId` (usually actor URL + #main-key)
             [$publicKeyData, $info] = \Federator\Main::getFromRemote($keyId, ['Accept: application/activity+json']);
 
@@ -233,11 +244,14 @@ class Api extends Main
             }
 
             $publicKeyPem = $actor['publicKey']['publicKeyPem'] ?? null;
-        }
 
-        if (!isset($publicKeyPem) || $publicKeyPem === false) {
-            http_response_code(500);
-            throw new Exceptions\PermissionDenied("Public key couldn't be determined");
+            if (!isset($publicKeyPem) || $publicKeyPem === false) {
+                http_response_code(500);
+                throw new Exceptions\PermissionDenied("Public key couldn't be determined");
+            }
+
+            // Cache the public key for 1 hour
+            $this->cache->savePublicKey($keyId, $publicKeyPem);
         }
 
         // Reconstruct the signed string
@@ -264,7 +278,7 @@ class Api extends Main
         }
         if ($verified != 1) {
             http_response_code(500);
-            throw new Exceptions\PermissionDenied("Signature verification failed for publicKey");
+            throw new Exceptions\PermissionDenied("Signature verification failed");
         }
 
         // Signature is valid!
diff --git a/php/federator/api/fedusers/inbox.php b/php/federator/api/fedusers/inbox.php
index 3d9a28a..627cf30 100644
--- a/php/federator/api/fedusers/inbox.php
+++ b/php/federator/api/fedusers/inbox.php
@@ -3,7 +3,7 @@
  * SPDX-FileCopyrightText: 2024 Sascha Nitsch (grumpydeveloper) https://contentnation.net/@grumpydevelop
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
- * @author Sascha Nitsch (grumpydeveloper)
+ * @author Yannis Vogel (vogeldevelopment)
  **/
 
 namespace Federator\Api\FedUsers;
diff --git a/php/federator/api/fedusers/outbox.php b/php/federator/api/fedusers/outbox.php
index 7bd7450..2dc4458 100644
--- a/php/federator/api/fedusers/outbox.php
+++ b/php/federator/api/fedusers/outbox.php
@@ -90,182 +90,11 @@ class Outbox implements \Federator\Api\FedUsers\FedUsersInterface
     /**
      * handle post call
      *
-     * @param string|null $_user user to add data to outbox
+     * @param string|null $_user user to add data to outbox @unused-param
      * @return string|false response
      */
     public function post($_user)
     {
-        $_rawInput = file_get_contents('php://input');
-
-        $allHeaders = getallheaders();
-        try {
-            $this->main->checkSignature($allHeaders);
-        } catch (\Federator\Exceptions\PermissionDenied $e) {
-            error_log("Outbox::post Signature check failed: " . $e->getMessage());
-            http_response_code(401);
-            return false;
-        }
-
-        $input = is_string($_rawInput) ? json_decode($_rawInput, true) : null;
-        $host = $_SERVER['SERVER_NAME'];
-        if (!is_array($input)) {
-            error_log("Outbox::post Input wasn't of type array");
-            return false;
-        }
-
-        if (isset($allHeaders['X-Sender']) && $allHeaders['X-Sender'] === $this->main->getConfig()['keys']['headerSenderName']) {
-            $outboxActivity = $this->main->getConnector()->jsonToActivity($input);
-        } else {
-            $outboxActivity = \Federator\Data\ActivityPub\Factory::newActivityFromJson($input);
-        }
-
-        if ($outboxActivity === false) {
-            error_log("Outbox::post couldn't create outboxActivity");
-            return false;
-        }
-
-        $sendTo = $outboxActivity->getCC();
-        if ($outboxActivity->getType() === 'Undo') {
-            $object = $outboxActivity->getObject();
-            if ($object !== null) {
-                $sendTo = $object->getCC();
-            }
-        }
-
-        $users = [];
-
-        foreach ($sendTo as $receiver) {
-            if ($receiver === '' || !is_string($receiver)) {
-                continue;
-            }
-
-            if (str_ends_with($receiver, '/followers')) {
-                $followers = $this->fetchAllFollowers($receiver, $host);
-                if (is_array($followers)) {
-                    $users = array_merge($users, $followers);
-                }
-            }
-        }
-
-        if (empty($users)) { // todo remove, debugging for now
-            $rootDir = $_SERVER['DOCUMENT_ROOT'] . '../';
-            // Save the raw input and parsed JSON to a file for inspection
-            file_put_contents(
-                $rootDir . 'logs/outbox.log',
-                date('Y-m-d H:i:s') . ": ==== POST Outbox Activity ====\n" . json_encode($outboxActivity, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT) . "\n\n",
-                FILE_APPEND
-            );
-        }
-        if ($_user !== false && !in_array($_user, $users, true)) {
-            $users[] = $_user;
-        }
-
-        foreach ($users as $user) {
-            if (!isset($user)) {
-                continue;
-            }
-
-            $this->postForUser($user, $outboxActivity);
-        }
-
-        return json_encode($outboxActivity, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT);
-    }
-
-    /**
-     * handle post call for specific user
-     *
-     * @param string $_user user to add data to outbox
-     * @param \Federator\Data\ActivityPub\Common\Activity $outboxActivity the activity that we received
-     * @return boolean response
-     */
-    private function postForUser($_user, $outboxActivity)
-    {
-        if (isset($_user)) {
-            $dbh = $this->main->getDatabase();
-            $cache = $this->main->getCache();
-            $connector = $this->main->getConnector();
-
-            // get user
-            $user = \Federator\DIO\User::getUserByName(
-                $dbh,
-                $_user,
-                $connector,
-                $cache
-            );
-            if ($user->id === null) {
-                error_log("Outbox::postForUser couldn't find user: $_user");
-                return false;
-            }
-        }
-
-        $rootDir = $_SERVER['DOCUMENT_ROOT'] . '../';
-        // Save the raw input and parsed JSON to a file for inspection
-        file_put_contents(
-            $rootDir . 'logs/outbox_' . $_user . '.log',
-            date('Y-m-d H:i:s') . ": ==== POST " . $_user . " Outbox Activity ====\n" . json_encode($outboxActivity, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT) . "\n\n",
-            FILE_APPEND
-        );
-
-        return true;
-    }
-
-    /**
-     * fetch all followers from url and return the ones that belong to our server
-     *
-     * @param string $collectionUrl The url of f.e. the posters followers
-     * @param string $host our current host-url
-     * @return string[] the names of the followers that are hosted on our server
-     */
-    private static function fetchAllFollowers(string $collectionUrl, string $host): array
-    {
-        $users = [];
-
-        [$collectionResponse, $collectionInfo] = \Federator\Main::getFromRemote($collectionUrl, ['Accept: application/activity+json']);
-        if ($collectionInfo['http_code'] != 200) {
-            error_log("Outbox::fetchAllFollowers Failed to fetch follower collection metadata from $collectionUrl");
-            return [];
-        }
-
-        $collectionData = json_decode($collectionResponse, true);
-        $nextPage = $collectionData['first'] ?? $collectionData['current'] ?? null;
-
-        if (!isset($nextPage)) {
-            error_log("Outbox::fetchAllFollowers No 'first' or 'current' page in collection at $collectionUrl");
-            return [];
-        }
-
-        // Loop through all pages
-        while ($nextPage) {
-            [$pageResponse, $pageInfo] = \Federator\Main::getFromRemote($nextPage, ['Accept: application/activity+json']);
-            if ($pageInfo['http_code'] != 200) {
-                error_log("Outbox::fetchAllFollowers Failed to fetch follower page at $nextPage");
-                break;
-            }
-
-            $pageData = json_decode($pageResponse, true);
-            $items = $pageData['orderedItems'] ?? $pageData['items'] ?? [];
-
-            foreach ($items as $followerUrl) {
-                $parts = parse_url($followerUrl);
-                if (!isset($parts['host']) || !str_ends_with($parts['host'], $host)) {
-                    continue;
-                }
-
-                [$actorResponse, $actorInfo] = \Federator\Main::getFromRemote($followerUrl, ['Accept: application/activity+json']);
-                if ($actorInfo['http_code'] != 200) {
-                    error_log("Outbox::fetchAllFollowers Failed to fetch actor data for follower: $followerUrl");
-                    continue;
-                }
-
-                $actorData = json_decode($actorResponse, true);
-                if (isset($actorData['preferredUsername'])) {
-                    $users[] = $actorData['preferredUsername'];
-                }
-            }
-
-            $nextPage = $pageData['next'] ?? null;
-        }
-
-        return $users;
+        return false;
     }
 }
diff --git a/php/federator/api/v1/newcontent.php b/php/federator/api/v1/newcontent.php
new file mode 100644
index 0000000..16a064f
--- /dev/null
+++ b/php/federator/api/v1/newcontent.php
@@ -0,0 +1,262 @@
+<?php
+/**
+ * SPDX-FileCopyrightText: 2024 Sascha Nitsch (grumpydeveloper) https://contentnation.net/@grumpydevelop
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * @author Yannis Vogel (vogeldevelopment)
+ **/
+
+namespace Federator\Api\V1;
+
+/**
+ * Called from our application to inform us about new content (f.e. new posts on contentnation.net)
+ */
+class NewContent implements \Federator\Api\APIInterface
+{
+    /**
+     * main instance
+     *
+     * @var \Federator\Api $main
+     */
+    private $main;
+
+    /**
+     * response from sub-calls
+     *
+     * @var string $response
+     */
+    private $response;
+
+    /**
+     * constructor
+     *
+     * @param \Federator\Main $main main instance
+     * @return void
+     */
+    public function __construct($main)
+    {
+        $this->main = $main;
+    }
+
+    /**
+     * run given url path
+     *
+     * @param array<string> $paths path array split by /
+     * @param \Federator\Data\User|false $user user who is calling us @unused-param
+     * @return bool true on success
+     */
+    public function exec($paths, $user)
+    {
+        $method = $_SERVER["REQUEST_METHOD"];
+        $_username = $paths[2];
+        if ($method === 'GET') { // unsupported
+            throw new \Federator\Exceptions\InvalidArgument("GET not supported");
+        }
+        switch (sizeof($paths)) {
+            case 3:
+                $ret = $this->post($_username);
+                break;
+        }
+
+        if (isset($ret) && $ret !== false) {
+            $this->response = $ret;
+            return true;
+        }
+
+        $this->main->setResponseCode(404);
+        return false;
+    }
+
+
+    /**
+     * handle post call
+     *
+     * @param string|null $_user user that triggered the post
+     * @return string|false response
+     */
+    public function post($_user)
+    {
+        error_log("NewContent::post called with user: $_user");
+        $_rawInput = file_get_contents('php://input');
+
+        $allHeaders = getallheaders();
+        try {
+            $this->main->checkSignature($allHeaders);
+        } catch (\Federator\Exceptions\PermissionDenied $e) {
+            error_log("NewContent::post Signature check failed: " . $e->getMessage());
+            http_response_code(401);
+            return false;
+        }
+
+        $input = is_string($_rawInput) ? json_decode($_rawInput, true) : null;
+        $host = $_SERVER['SERVER_NAME'];
+        if (!is_array($input)) {
+            error_log("NewContent::post Input wasn't of type array");
+            return false;
+        }
+
+        if (isset($allHeaders['X-Sender'])) {
+            $newActivity = $this->main->getConnector()->jsonToActivity($input);
+        } else {
+            $newActivity = \Federator\Data\ActivityPub\Factory::newActivityFromJson($input);
+        }
+
+        if ($newActivity === false) {
+            error_log("NewContent::post couldn't create newActivity");
+            return false;
+        }
+
+        $sendTo = $newActivity->getCC();
+        if ($newActivity->getType() === 'Undo') {
+            $object = $newActivity->getObject();
+            if ($object !== null) {
+                $sendTo = $object->getCC();
+            }
+        }
+
+        $users = [];
+
+        foreach ($sendTo as $receiver) {
+            if ($receiver === '' || !is_string($receiver)) {
+                continue;
+            }
+
+            if (str_ends_with($receiver, '/followers')) {
+                $followers = $this->fetchAllFollowers($receiver, $host);
+                if (is_array($followers)) {
+                    $users = array_merge($users, $followers);
+                }
+            }
+        }
+
+        if (empty($users)) { // todo remove, debugging for now
+            $rootDir = $_SERVER['DOCUMENT_ROOT'] . '../';
+            // Save the raw input and parsed JSON to a file for inspection
+            file_put_contents(
+                $rootDir . 'logs/newContent.log',
+                date('Y-m-d H:i:s') . ": ==== POST NewContent Activity ====\n" . json_encode($newActivity, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT) . "\n\n",
+                FILE_APPEND
+            );
+        }
+        if ($_user !== false && !in_array($_user, $users, true)) {
+            $users[] = $_user;
+        }
+
+        foreach ($users as $user) {
+            if (!isset($user)) {
+                continue;
+            }
+
+            $this->postForUser($user, $newActivity);
+        }
+
+        return json_encode($newActivity, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT);
+    }
+
+    /**
+     * handle post call for specific user
+     *
+     * @param string $_user user that triggered the post
+     * @param \Federator\Data\ActivityPub\Common\Activity $newActivity the activity that we received
+     * @return boolean response
+     */
+    private function postForUser($_user, $newActivity)
+    {
+        if (isset($_user)) {
+            $dbh = $this->main->getDatabase();
+            $cache = $this->main->getCache();
+            $connector = $this->main->getConnector();
+
+            // get user
+            $user = \Federator\DIO\User::getUserByName(
+                $dbh,
+                $_user,
+                $connector,
+                $cache
+            );
+            if ($user->id === null) {
+                error_log("NewContent::postForUser couldn't find user: $_user");
+                return false;
+            }
+        }
+
+        $rootDir = $_SERVER['DOCUMENT_ROOT'] . '../';
+        // Save the raw input and parsed JSON to a file for inspection
+        file_put_contents(
+            $rootDir . 'logs/newcontent_' . $_user . '.log',
+            date('Y-m-d H:i:s') . ": ==== POST " . $_user . " NewContent Activity ====\n" . json_encode($newActivity, JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT) . "\n\n",
+            FILE_APPEND
+        );
+
+        return true;
+    }
+
+    /**
+     * fetch all followers from url and return the ones that belong to our server
+     *
+     * @param string $collectionUrl The url of f.e. the posters followers
+     * @param string $host our current host-url
+     * @return string[] the names of the followers that are hosted on our server
+     */
+    private static function fetchAllFollowers(string $collectionUrl, string $host): array
+    {
+        $users = [];
+
+        [$collectionResponse, $collectionInfo] = \Federator\Main::getFromRemote($collectionUrl, ['Accept: application/activity+json']);
+        if ($collectionInfo['http_code'] != 200) {
+            error_log("NewContent::fetchAllFollowers Failed to fetch follower collection metadata from $collectionUrl");
+            return [];
+        }
+
+        $collectionData = json_decode($collectionResponse, true);
+        $nextPage = $collectionData['first'] ?? $collectionData['current'] ?? null;
+
+        if (!isset($nextPage)) {
+            error_log("NewContent::fetchAllFollowers No 'first' or 'current' page in collection at $collectionUrl");
+            return [];
+        }
+
+        // Loop through all pages
+        while ($nextPage) {
+            [$pageResponse, $pageInfo] = \Federator\Main::getFromRemote($nextPage, ['Accept: application/activity+json']);
+            if ($pageInfo['http_code'] != 200) {
+                error_log("NewContent::fetchAllFollowers Failed to fetch follower page at $nextPage");
+                break;
+            }
+
+            $pageData = json_decode($pageResponse, true);
+            $items = $pageData['orderedItems'] ?? $pageData['items'] ?? [];
+
+            foreach ($items as $followerUrl) {
+                $parts = parse_url($followerUrl);
+                if (!isset($parts['host']) || !str_ends_with($parts['host'], $host)) {
+                    continue;
+                }
+
+                [$actorResponse, $actorInfo] = \Federator\Main::getFromRemote($followerUrl, ['Accept: application/activity+json']);
+                if ($actorInfo['http_code'] != 200) {
+                    error_log("NewContent::fetchAllFollowers Failed to fetch actor data for follower: $followerUrl");
+                    continue;
+                }
+
+                $actorData = json_decode($actorResponse, true);
+                if (isset($actorData['preferredUsername'])) {
+                    $users[] = $actorData['preferredUsername'];
+                }
+            }
+
+            $nextPage = $pageData['next'] ?? null;
+        }
+
+        return $users;
+    }
+
+    /**
+     * get internal represenation as json string
+     * @return string json string or html
+     */
+    public function toJson()
+    {
+        return $this->response;
+    }
+}
\ No newline at end of file
diff --git a/php/federator/cache/cache.php b/php/federator/cache/cache.php
index 2d3b638..5f3878d 100644
--- a/php/federator/cache/cache.php
+++ b/php/federator/cache/cache.php
@@ -57,4 +57,21 @@ interface Cache extends \Federator\Connector\Connector
      * @return void
      */
     public function saveRemoteUserBySession($_session, $_user, $user);
+
+    /**
+     * Save the public key for a given keyId
+     *
+     * @param string $keyId The keyId (e.g., actor URL + #main-key)
+     * @param string $publicKeyPem The public key PEM to cache
+     * @return void
+     */
+    public function savePublicKey(string $keyId, string $publicKeyPem);
+
+    /**
+     * Retrieve the public key for a given keyId
+     *
+     * @param string $keyId The keyId (e.g., actor URL + #main-key)
+     * @return string|false The cached public key PEM or false if not found
+     */
+    public function getPublicKey(string $keyId);
 }
diff --git a/php/federator/connector/connector.php b/php/federator/connector/connector.php
index abee7eb..3a49c5a 100644
--- a/php/federator/connector/connector.php
+++ b/php/federator/connector/connector.php
@@ -64,4 +64,13 @@ interface Connector
      * @return \Federator\Data\ActivityPub\Common\Activity|false
      */
     public function jsonToActivity(array $jsonData);
+
+    /**
+     * check if the headers include a valid signature
+     *
+     * @param string[] $headers the headers
+     * @throws \Federator\Exceptions\PermissionDenied
+     * @return string|\Federator\Exceptions\PermissionDenied
+     */
+    public function checkSignature($headers);
 }
diff --git a/php/federator/data/activitypub/common/Announce.php b/php/federator/data/activitypub/common/Announce.php
index 4f18004..d50a932 100644
--- a/php/federator/data/activitypub/common/Announce.php
+++ b/php/federator/data/activitypub/common/Announce.php
@@ -3,7 +3,7 @@
  * SPDX-FileCopyrightText: 2024 Sascha Nitsch (grumpydeveloper) https://contentnation.net/@grumpydevelop
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
- * @author Sascha Nitsch (grumpydeveloper)
+ * @author Yannis Vogel (vogeldevelopment)
  **/
 
 namespace Federator\Data\ActivityPub\Common;
diff --git a/php/federator/data/activitypub/common/Undo.php b/php/federator/data/activitypub/common/Undo.php
index b4732d1..28ec50b 100644
--- a/php/federator/data/activitypub/common/Undo.php
+++ b/php/federator/data/activitypub/common/Undo.php
@@ -3,7 +3,7 @@
  * SPDX-FileCopyrightText: 2024 Sascha Nitsch (grumpydeveloper) https://contentnation.net/@grumpydevelop
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
- * @author Sascha Nitsch (grumpydeveloper)
+ * @author Yannis Vogel (vogeldevelopment)
  **/
 
 namespace Federator\Data\ActivityPub\Common;
diff --git a/php/federator/data/activitypub/common/outbox.php b/php/federator/data/activitypub/common/outbox.php
index 4439ebe..4519a8a 100644
--- a/php/federator/data/activitypub/common/outbox.php
+++ b/php/federator/data/activitypub/common/outbox.php
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
  * @author Sascha Nitsch (grumpydeveloper)
+ * @author Yannis Vogel (vogeldevelopment)
  **/
 
 namespace Federator\Data\ActivityPub\Common;
diff --git a/php/federator/dio/followers.php b/php/federator/dio/followers.php
index b1dfbfc..5972b1b 100644
--- a/php/federator/dio/followers.php
+++ b/php/federator/dio/followers.php
@@ -3,7 +3,7 @@
  * SPDX-FileCopyrightText: 2024 Sascha Nitsch (grumpydeveloper) https://contentnation.net/@grumpydevelop
  * SPDX-License-Identifier: GPL-3.0-or-later
  *
- * @author Sascha Nitsch (grumpydeveloper)
+ * @author Yannis Vogel (vogeldevelopment)
  **/
 
 namespace Federator\DIO;
diff --git a/plugins/federator/contentnation.php b/plugins/federator/contentnation.php
index 6afe12e..8775777 100644
--- a/plugins/federator/contentnation.php
+++ b/plugins/federator/contentnation.php
@@ -338,30 +338,128 @@ class ContentNation implements Connector
      */
     public function jsonToActivity(array $jsonData)
     {
+        // Common fields for all activity types
         $ap = [
             '@context' => 'https://www.w3.org/ns/activitystreams',
-            'type' => 'Create',
+            'type' => 'Create', // Default to 'Create'
             'id' => $jsonData['id'] ?? null,
-            'actor' => $jsonData['actor']['id'] ?? null,
+            'actor' => $jsonData['actor'] ?? null,
             'published' => $jsonData['object']['published'] ?? null,
             'to' => ['https://www.w3.org/ns/activitystreams#Public'],
             'cc' => [$jsonData['related']['cc']['followers'] ?? null],
-            'object' => [
-                'type' => 'Note',
-                'id' => $jsonData['object']['id'] ?? null,
-                'summary' => $jsonData['object']['summary'] ?? '',
-                'content' => $jsonData['object']['content'] ?? '',
-                'published' => $jsonData['object']['published'] ?? null,
-                'attributedTo' => $jsonData['actor']['id'] ?? null,
-                'to' => ['https://www.w3.org/ns/activitystreams#Public'],
-                'cc' => [$jsonData['related']['cc']['followers'] ?? null],
-                'url' => $jsonData['object']['url'] ?? null,
-                'inReplyTo' => $jsonData['related']['article']['id'] ?? null,
-            ],
         ];
 
+        // Handle specific fields based on the type
+        switch ($jsonData['type']) {
+            case 'comment':
+                $ap['object'] = [
+                    'type' => 'Note',
+                    'id' => $jsonData['object']['id'] ?? null,
+                    'summary' => $jsonData['object']['summary'] ?? '',
+                    'content' => $jsonData['object']['content'] ?? '',
+                    'published' => $jsonData['object']['published'] ?? null,
+                    'attributedTo' => $jsonData['actor']['id'] ?? null,
+                    'to' => ['https://www.w3.org/ns/activitystreams#Public'],
+                    'cc' => [$jsonData['related']['cc']['followers'] ?? null],
+                    'url' => $jsonData['object']['url'] ?? null,
+                    'inReplyTo' => $jsonData['related']['article']['id'] ?? null,
+                ];
+                break;
+
+            // todo fix this to properly handle votes, data is mocked for now
+            case 'vote':
+                // Handle voting on a comment or an article
+                if ($jsonData['object']['type'] === 'Comment') {
+                    $jsonData['object']['type'] = 'Note';
+                }
+                $ap['object'] = [
+                    'id' => $jsonData['object']['id'] ?? null,
+                    'type' => $jsonData['object']['type'] ?? 'Article',
+                ];
+
+                // Include additional fields if voting on an article
+                if ($ap['object']['type'] === 'Article') {
+                    $ap['object']['name'] = $jsonData['object']['name'] ?? null;
+                    $ap['object']['author'] = $jsonData['object']['author'] ?? null;
+                }
+
+                // Add vote-specific fields
+                $ap['vote'] = [
+                    'value' => $jsonData['vote']['value'] ?? null,
+                    'type' => $jsonData['vote']['type'] ?? null,
+                ];
+                break;
+
+            default:
+                // Handle unsupported types or fallback to default behavior
+                throw new \InvalidArgumentException("Unsupported activity type: {$jsonData['type']}");
+        }
+
         return \Federator\Data\ActivityPub\Factory::newActivityFromJson($ap);
     }
+
+    /**
+     * check if the headers include a valid signature
+     *
+     * @param string[] $headers the headers
+     * @throws \Federator\Exceptions\PermissionDenied
+     * @return string|\Federator\Exceptions\PermissionDenied
+     */
+    public function checkSignature($headers)
+    {
+        $signatureHeader = $headers['Signature'] ?? null;
+
+        if (!isset($signatureHeader)) {
+            throw new \Federator\Exceptions\PermissionDenied("Missing Signature header");
+        }
+
+        if (!isset($headers['X-Sender']) || $headers['X-Sender'] !== $this->config['keys']['headerSenderName'])
+        {
+            throw new \Federator\Exceptions\PermissionDenied("Invalid sender name");
+        }
+
+        // Parse Signature header
+        preg_match_all('/(\w+)=["\']?([^"\',]+)["\']?/', $signatureHeader, $matches);
+        $signatureParts = array_combine($matches[1], $matches[2]);
+
+        $signature = base64_decode($signatureParts['signature']);
+        $signedHeaders = explode(' ', $signatureParts['headers']);
+
+        $pKeyPath = $_SERVER['DOCUMENT_ROOT'] . $this->config['keys']['publicKeyPath'];
+        $publicKeyPem = file_get_contents($pKeyPath);
+        if ($publicKeyPem === false) {
+            http_response_code(500);
+            throw new \Federator\Exceptions\PermissionDenied("Public key couldn't be determined");
+        }
+
+        // Reconstruct the signed string
+        $signedString = '';
+        foreach ($signedHeaders as $header) {
+            if ($header === '(request-target)') {
+                $method = strtolower($_SERVER['REQUEST_METHOD']);
+                $path = $_SERVER['REQUEST_URI'];
+                $headerValue = "$method $path";
+            } else {
+                $headerValue = $headers[ucwords($header, '-')] ?? '';
+            }
+
+            $signedString .= strtolower($header) . ": " . $headerValue . "\n";
+        }
+
+        $signedString = rtrim($signedString);
+
+        // Verify the signature
+        $pubkeyRes = openssl_pkey_get_public($publicKeyPem);
+        $verified = false;
+        if ($pubkeyRes instanceof \OpenSSLAsymmetricKey && is_string($signature)) {
+            $verified = openssl_verify($signedString, $signature, $pubkeyRes, OPENSSL_ALGO_SHA256);
+        }
+        if ($verified != 1) {
+            http_response_code(500);
+            throw new \Federator\Exceptions\PermissionDenied("Signature verification failed");
+        }
+        return "Signature verified.";
+    }
 }
 
 namespace Federator;
diff --git a/plugins/federator/dummyconnector.php b/plugins/federator/dummyconnector.php
index c621baf..2871f70 100644
--- a/plugins/federator/dummyconnector.php
+++ b/plugins/federator/dummyconnector.php
@@ -95,6 +95,18 @@ class DummyConnector implements Connector
         $user->session = $_session;
         return $user;
     }
+
+    /**
+     * check if the headers include a valid signature
+     *
+     * @param string[] $headers the headers @unused-param
+     * @throws \Federator\Exceptions\PermissionDenied
+     * @return string|\Federator\Exceptions\PermissionDenied
+     */
+    public function checkSignature($headers)
+    {
+        return new \Federator\Exceptions\PermissionDenied("Dummy connector: no signature check");
+    }
 }
 
 namespace Federator;
diff --git a/plugins/federator/rediscache.php b/plugins/federator/rediscache.php
index 0acccab..6768e2a 100644
--- a/plugins/federator/rediscache.php
+++ b/plugins/federator/rediscache.php
@@ -41,6 +41,13 @@ class RedisCache implements Cache
      */
     private $userTTL;
 
+    /**
+     * public key cache time to live in secods
+     *
+     * @var int $publicKeyPemTTL
+     */
+    private $publicKeyPemTTL;
+
     /**
      * constructor
      */
@@ -50,6 +57,7 @@ class RedisCache implements Cache
         if ($config !== false) {
             $this->config = $config;
             $this->userTTL = array_key_exists('userttl', $config) ? intval($config['userttl'], 10) : 60;
+            $this->publicKeyPemTTL = array_key_exists('publickeypemttl', $config) ? intval($config['publickeypemttl'], 10) : 3600;
         }
     }
 
@@ -176,6 +184,21 @@ class RedisCache implements Cache
         return $user;
     }
 
+    /**
+     * Retrieve the public key for a given keyId
+     *
+     * @param string $keyId The keyId (e.g., actor URL + #main-key)
+     * @return string|false The cached public key PEM or false if not found
+     */
+    public function getPublicKey(string $keyId)
+    {
+        if (!$this->connected) {
+            $this->connect();
+        }
+        $key = self::createKey('publickey', $keyId);
+        return $this->redis->get($key);
+    }
+
     /**
      * save remote followers by user
      *
@@ -243,6 +266,34 @@ class RedisCache implements Cache
         $serialized = $user->toJson();
         $this->redis->setEx($key, $this->userTTL, $serialized,);
     }
+
+    /**
+     * Save the public key for a given keyId
+     *
+     * @param string $keyId The keyId (e.g., actor URL + #main-key)
+     * @param string $publicKeyPem The public key PEM to cache
+     * @return void
+     */
+    public function savePublicKey(string $keyId, string $publicKeyPem)
+    {
+        if (!$this->connected) {
+            $this->connect();
+        }
+        $key = self::createKey('publickey', $keyId);
+        $this->redis->setEx($key, $this->publicKeyPemTTL, $publicKeyPem); // TTL = 1 hour
+    }
+
+    /**
+     * check if the headers include a valid signature
+     *
+     * @param string[] $headers the headers @unused-param
+     * @throws \Federator\Exceptions\PermissionDenied
+     * @return string|\Federator\Exceptions\PermissionDenied
+     */
+    public function checkSignature($headers)
+    {
+        return new \Federator\Exceptions\PermissionDenied("RedisCache: no signature check");
+    }
 }
 
 namespace Federator;
diff --git a/rediscache.ini b/rediscache.ini
index 5d55955..1d97d0c 100644
--- a/rediscache.ini
+++ b/rediscache.ini
@@ -2,6 +2,6 @@
 host = localhost
 port = 6379
 username = federator
-password = redis*change*password
 userttl = 10
+publickeypemttl = 3600
 statsttl = 60