diff --git a/lib/Interfaces/Actor/PersonInterface.php b/lib/Interfaces/Actor/PersonInterface.php
index 6e22a0da..48f36793 100644
--- a/lib/Interfaces/Actor/PersonInterface.php
+++ b/lib/Interfaces/Actor/PersonInterface.php
@@ -171,6 +171,5 @@ class PersonInterface implements IActivityPubInterface {
 		$this->cacheActorsRequest->deleteFromId($item->getId());
 	}
 
-
 }
 
diff --git a/lib/Model/ActivityPub/ACore.php b/lib/Model/ActivityPub/ACore.php
index 4f981840..7eb48a58 100644
--- a/lib/Model/ActivityPub/ACore.php
+++ b/lib/Model/ActivityPub/ACore.php
@@ -32,6 +32,7 @@ namespace OCA\Social\Model\ActivityPub;
 
 use daita\MySmallPhpTools\Traits\TArrayTools;
 use daita\MySmallPhpTools\Traits\TPathTools;
+use daita\MySmallPhpTools\Traits\TStringTools;
 use JsonSerializable;
 use OCA\Social\Exceptions\ActivityCantBeVerifiedException;
 use OCA\Social\Exceptions\InvalidOriginException;
@@ -45,6 +46,7 @@ class ACore extends Item implements JsonSerializable {
 
 
 	use TArrayTools;
+	use TStringTools;
 	use TPathTools;
 
 
@@ -238,11 +240,7 @@ class ACore extends Item implements JsonSerializable {
 			$base = $this->withoutEndSlash($this->withBeginSlash($base));
 		}
 
-		$uuid = sprintf(
-			'%04x%04x-%04x-%04x-%04x-%04x%04x%04x', mt_rand(0, 0xffff), mt_rand(0, 0xffff),
-			mt_rand(0, 0xffff), mt_rand(0, 0xfff) | 0x4000, mt_rand(0, 0x3fff) | 0x8000,
-			mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
-		);
+		$uuid = $this->uuid();
 
 		$this->setId($url . $base . '/' . $uuid);
 	}
diff --git a/lib/Model/RequestQueue.php b/lib/Model/RequestQueue.php
index afe0c1f5..a3fd0365 100644
--- a/lib/Model/RequestQueue.php
+++ b/lib/Model/RequestQueue.php
@@ -32,6 +32,7 @@ namespace OCA\Social\Model;
 
 
 use daita\MySmallPhpTools\Traits\TArrayTools;
+use daita\MySmallPhpTools\Traits\TStringTools;
 use DateTime;
 use JsonSerializable;
 
@@ -45,6 +46,7 @@ class RequestQueue implements JsonSerializable {
 
 
 	use TArrayTools;
+	use TStringTools;
 
 
 	const STATUS_STANDBY = 0;
@@ -162,11 +164,7 @@ class RequestQueue implements JsonSerializable {
 	 * @return RequestQueue
 	 */
 	public function resetToken(): RequestQueue {
-		$uuid = sprintf(
-			'%04x%04x-%04x-%04x-%04x-%04x%04x%04x', mt_rand(0, 0xffff), mt_rand(0, 0xffff),
-			mt_rand(0, 0xffff), mt_rand(0, 0xfff) | 0x4000, mt_rand(0, 0x3fff) | 0x8000,
-			mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
-		);
+		$uuid = $this->uuid();
 
 		$this->setToken($uuid);
 
diff --git a/lib/Service/CacheDocumentService.php b/lib/Service/CacheDocumentService.php
index 8f5c3fe0..cf861a2f 100644
--- a/lib/Service/CacheDocumentService.php
+++ b/lib/Service/CacheDocumentService.php
@@ -33,6 +33,7 @@ namespace OCA\Social\Service;
 use daita\MySmallPhpTools\Exceptions\MalformedArrayException;
 use daita\MySmallPhpTools\Model\Request;
 use daita\MySmallPhpTools\Traits\TArrayTools;
+use daita\MySmallPhpTools\Traits\TStringTools;
 use Exception;
 use OCA\Social\Exceptions\CacheContentException;
 use OCA\Social\Exceptions\CacheContentMimeTypeException;
@@ -52,6 +53,7 @@ class CacheDocumentService {
 
 
 	use TArrayTools;
+	use TStringTools;
 
 
 	/** @var IAppData */
@@ -103,11 +105,7 @@ class CacheDocumentService {
 	 */
 	public function saveRemoteFileToCache(string $url, &$mime = '') {
 
-		$filename = sprintf(
-			'%04x%04x-%04x-%04x-%04x-%04x%04x%04x', mt_rand(0, 0xffff), mt_rand(0, 0xffff),
-			mt_rand(0, 0xffff), mt_rand(0, 0xfff) | 0x4000, mt_rand(0, 0x3fff) | 0x8000,
-			mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
-		);
+		$filename = $this->uuid();
 
 		// creating a path aa/bb/cc/dd/ from the filename aabbccdd-0123-[...]
 		$path = chunk_split(substr($filename, 0, 8), 2, '/');