diff --git a/include/api.php b/include/api.php
index 0f7fa85bdd..10ee292871 100644
--- a/include/api.php
+++ b/include/api.php
@@ -43,6 +43,7 @@ use Friendica\Protocol\Diaspora;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 require_once 'include/conversation.php';
@@ -4802,7 +4803,7 @@ function api_friendica_remoteauth()
 		$dfrn_id = '0:' . $orig_id;
 	}
 
-	$sec = random_string();
+	$sec = Strings::getRandomHex();
 
 	$fields = ['uid' => api_user(), 'cid' => $cid, 'dfrn_id' => $dfrn_id,
 		'sec' => $sec, 'expire' => time() + 45];
diff --git a/include/enotify.php b/include/enotify.php
index d6ca123271..2033027e3d 100644
--- a/include/enotify.php
+++ b/include/enotify.php
@@ -15,6 +15,7 @@ use Friendica\Model\Contact;
 use Friendica\Model\Item;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Emailer;
+use Friendica\Util\Strings;
 
 /**
  * @brief Creates a notification entry and possibly sends a mail
@@ -457,7 +458,7 @@ function notification($params)
 		Logger::log("adding notification entry", Logger::DEBUG);
 		do {
 			$dups = false;
-			$hash = random_string();
+			$hash = Strings::getRandomHex();
 			if (DBA::exists('notify', ['hash' => $hash])) {
 				$dups = true;
 			}
diff --git a/include/items.php b/include/items.php
index 9929f535f0..adc5bf0133 100644
--- a/include/items.php
+++ b/include/items.php
@@ -21,6 +21,7 @@ use Friendica\Protocol\OStatus;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
 use Friendica\Util\ParseUrl;
+use Friendica\Util\Strings;
 use Friendica\Util\Temporal;
 
 require_once 'include/text.php';
@@ -308,7 +309,7 @@ function subscribe_to_hub($url, array $importer, array $contact, $hubmode = 'sub
 	$push_url = System::baseUrl() . '/pubsub/' . $user['nickname'] . '/' . $contact['id'];
 
 	// Use a single verify token, even if multiple hubs
-	$verify_token = ((strlen($contact['hub-verify'])) ? $contact['hub-verify'] : random_string());
+	$verify_token = ((strlen($contact['hub-verify'])) ? $contact['hub-verify'] : Strings::getRandomHex());
 
 	$params= 'hub.mode=' . $hubmode . '&hub.callback=' . urlencode($push_url) . '&hub.topic=' . urlencode($contact['poll']) . '&hub.verify=async&hub.verify_token=' . $verify_token;
 
diff --git a/mod/dfrn_confirm.php b/mod/dfrn_confirm.php
index 0f001b11a2..8d4594c152 100644
--- a/mod/dfrn_confirm.php
+++ b/mod/dfrn_confirm.php
@@ -33,6 +33,7 @@ use Friendica\Protocol\ActivityPub;
 use Friendica\Util\Crypto;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 require_once 'include/enotify.php';
@@ -263,7 +264,7 @@ function dfrn_confirm_post(App $a, $handsfree = null)
 					break;
 				case 1:
 					// birthday paradox - generate new dfrn-id and fall through.
-					$new_dfrn_id = random_string();
+					$new_dfrn_id = Strings::getRandomHex();
 					q("UPDATE contact SET `issued-id` = '%s' WHERE `id` = %d AND `uid` = %d",
 						DBA::escape($new_dfrn_id),
 						intval($contact_id),
diff --git a/mod/dfrn_notify.php b/mod/dfrn_notify.php
index b14c71fb86..ba2332bcb1 100644
--- a/mod/dfrn_notify.php
+++ b/mod/dfrn_notify.php
@@ -14,6 +14,7 @@ use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Protocol\DFRN;
 use Friendica\Protocol\Diaspora;
+use Friendica\Util\Strings;
 
 require_once 'include/items.php';
 
@@ -267,7 +268,7 @@ function dfrn_notify_content(App $a) {
 			$dfrn_id = substr($dfrn_id,2);
 		}
 
-		$hash = random_string();
+		$hash = Strings::getRandomHex();
 
 		$status = 0;
 
diff --git a/mod/dfrn_poll.php b/mod/dfrn_poll.php
index a961506d17..9cd110917f 100644
--- a/mod/dfrn_poll.php
+++ b/mod/dfrn_poll.php
@@ -14,6 +14,7 @@ use Friendica\Module\Login;
 use Friendica\Protocol\DFRN;
 use Friendica\Protocol\OStatus;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 require_once 'include/items.php';
@@ -415,7 +416,7 @@ function dfrn_poll_content(App $a)
 
 	if ($dfrn_id != '') {
 		// initial communication from external contact
-		$hash = random_string();
+		$hash = Strings::getRandomHex();
 
 		$status = 0;
 
diff --git a/mod/dfrn_request.php b/mod/dfrn_request.php
index fdb1a42ee2..e5d5a3fe22 100644
--- a/mod/dfrn_request.php
+++ b/mod/dfrn_request.php
@@ -28,6 +28,7 @@ use Friendica\Module\Login;
 use Friendica\Network\Probe;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 
 require_once 'include/enotify.php';
 
@@ -320,7 +321,7 @@ function dfrn_request_post(App $a)
 				}
 			}
 
-			$issued_id = random_string();
+			$issued_id = Strings::getRandomHex();
 
 			if (is_array($contact_record)) {
 				// There is a contact record but no issued-id, so this
@@ -415,7 +416,7 @@ function dfrn_request_post(App $a)
 				return;
 			}
 
-			$hash = random_string() . (string) time();   // Generate a confirm_key
+			$hash = Strings::getRandomHex() . (string) time();   // Generate a confirm_key
 
 			if (is_array($contact_record)) {
 				$ret = q("INSERT INTO `intro` ( `uid`, `contact-id`, `blocked`, `knowyou`, `note`, `hash`, `datetime`)
diff --git a/mod/fsuggest.php b/mod/fsuggest.php
index 35710bb338..f87046f6c9 100644
--- a/mod/fsuggest.php
+++ b/mod/fsuggest.php
@@ -9,6 +9,7 @@ use Friendica\Core\L10n;
 use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\Util\DateTimeFormat;
+use Friendica\Util\Strings;
 
 function fsuggest_post(App $a)
 {
@@ -34,7 +35,7 @@ function fsuggest_post(App $a)
 
 	$new_contact = intval($_POST['suggest']);
 
-	$hash = random_string();
+	$hash = Strings::getRandomHex();
 
 	$note = escape_tags(trim(defaults($_POST, 'note', '')));
 
diff --git a/mod/pubsubhubbub.php b/mod/pubsubhubbub.php
index ea27f04822..26a157e2fd 100644
--- a/mod/pubsubhubbub.php
+++ b/mod/pubsubhubbub.php
@@ -93,7 +93,7 @@ function pubsubhubbub_init(App $a) {
 		}
 
 		// do subscriber verification according to the PuSH protocol
-		$hub_challenge = random_string(40);
+		$hub_challenge = Strings::getRandomHex(40);
 		$params = 'hub.mode=' .
 			($subscribe == 1 ? 'subscribe' : 'unsubscribe') .
 			'&hub.topic=' . urlencode($hub_topic) .
diff --git a/mod/redir.php b/mod/redir.php
index 088a5f55e3..6077a26f9a 100644
--- a/mod/redir.php
+++ b/mod/redir.php
@@ -8,6 +8,7 @@ use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Model\Profile;
+use Friendica\Util\Strings;
 
 function redir_init(App $a) {
 
@@ -93,7 +94,7 @@ function redir_init(App $a) {
 				$dfrn_id = '0:' . $orig_id;
 			}
 
-			$sec = random_string();
+			$sec = Strings::getRandomHex();
 
 			$fields = ['uid' => local_user(), 'cid' => $cid, 'dfrn_id' => $dfrn_id,
 				'sec' => $sec, 'expire' => time() + 45];
diff --git a/mod/removeme.php b/mod/removeme.php
index c2ceb7d4cf..44671ef073 100644
--- a/mod/removeme.php
+++ b/mod/removeme.php
@@ -68,7 +68,7 @@ function removeme_content(App $a)
 		$a->internalRedirect();
 	}
 
-	$hash = random_string();
+	$hash = Strings::getRandomHex();
 
 	require_once("mod/settings.php");
 	settings_init($a);
diff --git a/spec/dfrn2_contact_request.svg b/spec/dfrn2_contact_request.svg
index cc78be55c8..34de340f33 100644
--- a/spec/dfrn2_contact_request.svg
+++ b/spec/dfrn2_contact_request.svg
@@ -38,7 +38,7 @@ text { font:12px Dialog; }
 <text x="904" y="1084" style="font:13px Open Sans">where self = 0 to look if this contact is already there (if </text>
 <text x="904" y="1107" style="font:13px Open Sans">issued-id or rel is already available return here because it </text>
 <text x="904" y="1130" style="font:13px Open Sans">seems that we are already connected)</text>
-<text x="904" y="1176" style="font:13px Open Sans">- create a issued-id with $issued_id = random_string();</text>
+<text x="904" y="1176" style="font:13px Open Sans">- create a issued-id with $issued_id = Strings::getRandomHex();</text>
 <text x="904" y="1222" style="font:13px Open Sans">- if we already found a contact record above update the </text>
 <text x="904" y="1245" style="font:13px Open Sans">issued-id with the one we have created</text>
 <text x="904" y="1291" style="font:13px Open Sans">- otherwise if Bob is not already in the contact table scrape </text>
diff --git a/src/Content/Text/HTML.php b/src/Content/Text/HTML.php
index cdfd41c11f..9b73da56df 100644
--- a/src/Content/Text/HTML.php
+++ b/src/Content/Text/HTML.php
@@ -7,6 +7,7 @@ namespace Friendica\Content\Text;
 
 use DOMDocument;
 use DOMXPath;
+use Friendica\Content\Feature;
 use Friendica\Core\Addon;
 use Friendica\Core\L10n;
 use Friendica\Core\Config;
@@ -17,9 +18,9 @@ use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Util\Network;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 use League\HTMLToMarkdown\HtmlConverter;
-use Friendica\Content\Feature;
 
 class HTML
 {
@@ -1011,7 +1012,7 @@ class HTML
 			$tpl = Renderer::getMarkupTemplate('wall/content_filter.tpl');
 			$html = Renderer::replaceMacros($tpl, [
 				'$reasons'   => $reasons,
-				'$rnd'       => random_string(8),
+				'$rnd'       => Strings::getRandomHex(8),
 				'$openclose' => L10n::t('Click to open/close'),
 				'$html'      => $html
 			]);
diff --git a/src/Model/Contact.php b/src/Model/Contact.php
index 5d571e30e1..1a6349d9ca 100644
--- a/src/Model/Contact.php
+++ b/src/Model/Contact.php
@@ -25,6 +25,7 @@ use Friendica\Protocol\PortableContact;
 use Friendica\Protocol\Salmon;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 
 require_once 'boot.php';
 require_once 'include/dba.php';
@@ -1889,7 +1890,7 @@ class Contact extends BaseObject
 			$user = DBA::selectFirst('user', $fields, ['uid' => $importer['uid']]);
 			if (DBA::isResult($user) && !in_array($user['page-flags'], [self::PAGE_SOAPBOX, self::PAGE_FREELOVE, self::PAGE_COMMUNITY])) {
 				// create notification
-				$hash = random_string();
+				$hash = Strings::getRandomHex();
 
 				if (is_array($contact_record)) {
 					DBA::insert('intro', ['uid' => $importer['uid'], 'contact-id' => $contact_record['id'],
diff --git a/src/Model/Item.php b/src/Model/Item.php
index 1eb96609f2..35dfb7264c 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -33,6 +33,7 @@ use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Map;
 use Friendica\Util\XML;
 use Friendica\Util\Security;
+use Friendica\Util\Strings;
 use Text_LanguageDetect;
 
 require_once 'boot.php';
@@ -3479,7 +3480,7 @@ class Item extends BaseObject
 
 		while ((strpos($s, $spoilersearch) !== false)) {
 			$pos = strpos($s, $spoilersearch);
-			$rnd = random_string(8);
+			$rnd = Strings::getRandomHex(8);
 			$spoilerreplace = '<br /> <span id="spoiler-wrap-' . $rnd . '" class="spoiler-wrap fakelink" onclick="openClose(\'spoiler-' . $rnd . '\');">' . L10n::t('Click to open/close') . '</span>'.
 						'<blockquote class="spoiler" id="spoiler-' . $rnd . '" style="display: none;">';
 			$s = substr($s, 0, $pos) . $spoilerreplace . substr($s, $pos + strlen($spoilersearch));
@@ -3490,7 +3491,7 @@ class Item extends BaseObject
 
 		while ((strpos($s, $authorsearch) !== false)) {
 			$pos = strpos($s, $authorsearch);
-			$rnd = random_string(8);
+			$rnd = Strings::getRandomHex(8);
 			$authorreplace = '<br /> <span id="author-wrap-' . $rnd . '" class="author-wrap fakelink" onclick="openClose(\'author-' . $rnd . '\');">' . L10n::t('Click to open/close') . '</span>'.
 						'<blockquote class="author" id="author-' . $rnd . '" style="display: block;">';
 			$s = substr($s, 0, $pos) . $authorreplace . substr($s, $pos + strlen($authorsearch));
diff --git a/src/Model/Register.php b/src/Model/Register.php
index e54db87a6b..5311c80c26 100644
--- a/src/Model/Register.php
+++ b/src/Model/Register.php
@@ -7,6 +7,7 @@ namespace Friendica\Model;
 
 use Friendica\Database\DBA;
 use Friendica\Util\DateTimeFormat;
+use Friendica\Util\Strings;
 
 /**
  * Class interacting with the register database table
@@ -100,7 +101,7 @@ class Register
 	 */
 	public static function createForApproval($uid, $language, $note = '')
 	{
-		$hash = random_string();
+		$hash = Strings::getRandomHex();
 
 		if (!User::exists($uid)) {
 			return false;
diff --git a/src/Module/Magic.php b/src/Module/Magic.php
index b8af1f9614..01c5d5d464 100644
--- a/src/Module/Magic.php
+++ b/src/Module/Magic.php
@@ -11,6 +11,7 @@ use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Util\HTTPSignature;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 
 /**
  * Magic Auth (remote authentication) module.
@@ -74,7 +75,7 @@ class Magic extends BaseModule
 
 				$headers = [];
 				$headers['Accept'] = 'application/x-dfrn+json';
-				$headers['X-Open-Web-Auth'] = random_string();
+				$headers['X-Open-Web-Auth'] = Strings::getRandomHex();
 
 				// Create a header that is signed with the local users private key.
 				$headers = HTTPSignature::createSig(
diff --git a/src/Module/Owa.php b/src/Module/Owa.php
index a1dbfa2f31..8832dd9b0d 100644
--- a/src/Module/Owa.php
+++ b/src/Module/Owa.php
@@ -11,6 +11,7 @@ use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Model\OpenWebAuthToken;
 use Friendica\Util\HTTPSignature;
+use Friendica\Util\Strings;
 
 /**
  * @brief OpenWebAuth verifier and token generator
@@ -62,7 +63,7 @@ class Owa extends BaseModule
 								Logger::log('OWA success: ' . $contact['addr'], Logger::DATA);
 
 								$ret['success'] = true;
-								$token = random_string(32);
+								$token = Strings::getRandomHex(32);
 
 								// Store the generated token in the databe.
 								OpenWebAuthToken::create('owt', 0, $token, $contact['addr']);
diff --git a/src/Network/Probe.php b/src/Network/Probe.php
index fc93524bfd..a9a7a93ab9 100644
--- a/src/Network/Probe.php
+++ b/src/Network/Probe.php
@@ -24,6 +24,7 @@ use Friendica\Protocol\ActivityPub;
 use Friendica\Util\Crypto;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 use DomXPath;
 
@@ -1648,8 +1649,8 @@ class Probe
 		$data["nick"]    = $data["name"];
 		$data["photo"]   = Network::lookupAvatarByEmail($uri);
 		$data["url"]     = 'mailto:'.$uri;
-		$data["notify"]  = 'smtp '.random_string();
-		$data["poll"]    = 'email '.random_string();
+		$data["notify"]  = 'smtp ' . Strings::getRandomHex();
+		$data["poll"]    = 'email ' . Strings::getRandomHex();
 
 		$x = Email::messageMeta($mbox, $msgs[0]);
 		if (stristr($x[0]->from, $uri)) {
diff --git a/src/Protocol/DFRN.php b/src/Protocol/DFRN.php
index 8a2b21745d..c9ad69cc10 100644
--- a/src/Protocol/DFRN.php
+++ b/src/Protocol/DFRN.php
@@ -33,6 +33,7 @@ use Friendica\Object\Image;
 use Friendica\Util\Crypto;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 use HTMLPurifier;
 use HTMLPurifier_Config;
@@ -2009,7 +2010,7 @@ class DFRN
 
 		$fid = $r[0]["id"];
 
-		$hash = random_string();
+		$hash = Strings::getRandomHex();
 
 		$r = q(
 			"INSERT INTO `intro` (`uid`, `fid`, `contact-id`, `note`, `hash`, `datetime`, `blocked`)
@@ -3030,7 +3031,7 @@ class DFRN
 				return;
 			}
 
-			$sec = random_string();
+			$sec = Strings::getRandomHex();
 
 			DBA::insert('profile_check', ['uid' => local_user(), 'cid' => $cid, 'dfrn_id' => $dfrn_id, 'sec' => $sec, 'expire' => time() + 45]);
 
diff --git a/src/Protocol/Diaspora.php b/src/Protocol/Diaspora.php
index 0b5c9c9496..8fc17f97d1 100644
--- a/src/Protocol/Diaspora.php
+++ b/src/Protocol/Diaspora.php
@@ -34,6 +34,7 @@ use Friendica\Util\Crypto;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Map;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 use SimpleXMLElement;
 
@@ -2421,7 +2422,7 @@ class Diaspora
 		if (in_array($importer["page-flags"], [Contact::PAGE_NORMAL, Contact::PAGE_PRVGROUP])) {
 			Logger::log("Sending intra message for author ".$author.".", Logger::DEBUG);
 
-			$hash = random_string().(string)time();   // Generate a confirm_key
+			$hash = Strings::getRandomHex().(string)time();   // Generate a confirm_key
 
 			$ret = q(
 				"INSERT INTO `intro` (`uid`, `contact-id`, `blocked`, `knowyou`, `note`, `hash`, `datetime`)
@@ -3055,7 +3056,7 @@ class Diaspora
 			return 200;
 		}
 
-		$logid = random_string(4);
+		$logid = String::getRandomHex(4);
 
 		$dest_url = ($public_batch ? $contact["batch"] : $contact["notify"]);
 
diff --git a/src/Util/LDSignature.php b/src/Util/LDSignature.php
index e53590cf31..c9fde441fd 100644
--- a/src/Util/LDSignature.php
+++ b/src/Util/LDSignature.php
@@ -54,7 +54,7 @@ class LDSignature
 	{
 		$options = [
 			'type' => 'RsaSignature2017',
-			'nonce' => random_string(64),
+			'nonce' => Strings::getRandomHex(64),
 			'creator' => $owner['url'] . '#main-key',
 			'created' => DateTimeFormat::utcNow(DateTimeFormat::ATOM)
 		];
diff --git a/src/Util/Strings.php b/src/Util/Strings.php
index 8df9f585d1..ceb1a946a1 100644
--- a/src/Util/Strings.php
+++ b/src/Util/Strings.php
@@ -16,7 +16,7 @@ class Strings
      * @param int $size
      * @return string
      */
-    public static function getRandomHex($size = 64) // random_string()
+    public static function getRandomHex($size = 64)
     {
         $byte_size = ceil($size / 2);