diff --git a/app.php b/app.php
index 3e72024..c1f1427 100644
--- a/app.php
+++ b/app.php
@@ -82,6 +82,7 @@ $f3->route('GET /signature',
             $f3->set('noSharingMode', true);
         }
         $f3->set('activeTab', 'sign');
+
         echo View::instance()->render('signature.html.php');
     }
 );
@@ -241,11 +242,12 @@ $f3->route('POST /share',
         }
         if (!isset($_COOKIE[$hash])) {
             $symmetric_key = createSymmetricKey();
-            setcookie($hash, $symmetric_key, ['expires' => 0, 'samesite' => 'Strict', 'path' => "/"]);
+            $keyCookieDate = strtotime('+1 year');
+            setcookie($hash, $symmetric_key, ['expires' => $keyCookieDate, 'samesite' => 'Strict', 'path' => "/"]);
         }
         $encryptor = new CryptographyClass($symmetric_key);
         $encryptor->encrypt($hash);
-        $f3->reroute($f3->get('REVERSE_PROXY_URL').'/signature/'.$hash."#informations");
+        $f3->reroute($f3->get('REVERSE_PROXY_URL').'/signature/'.$hash."#sk:".$symmetric_key);
     }
 
 );
@@ -256,7 +258,11 @@ $f3->route('GET /signature/@hash/pdf',
         $hash = Web::instance()->slug($f3->get('PARAMS.hash'));
         $sharingFolder = $f3->get('PDF_STORAGE_PATH').$hash;
 
-        $cryptor = new CryptographyClass($_COOKIE[$hash]);
+        if (substr($_COOKIE[$hash], 0, 4) !== '#sk:') {
+            echo "Error: Invalid prefix.";
+            exit;
+        }
+        $cryptor = new CryptographyClass(substr($_COOKIE[$hash], 4, 15));
         $cryptor->decrypt($hash);
 
         $files = scandir($sharingFolder);
diff --git a/public/js/signature.js b/public/js/signature.js
index c323569..b6ef42b 100644
--- a/public/js/signature.js
+++ b/public/js/signature.js
@@ -411,6 +411,7 @@ var displaysSVG = function() {
     });
 };
 
+
 function dataURLtoBlob(dataurl) {
     let arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
         bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
@@ -944,7 +945,7 @@ var createEventsListener = function() {
         return true;
     });
 
-    if(hash) {
+    if(pdfHash) {
         updateNbLayers();
         setInterval(function() {
             updateNbLayers();
@@ -1063,12 +1064,12 @@ var pageUpload = async function() {
 
 var updateNbLayers = function() {
     const xhr = new XMLHttpRequest();
-    xhr.open('GET', '/signature/'+hash+'/nblayers', true);
+    xhr.open('GET', '/signature/'+pdfHash+'/nblayers', true);
     xhr.onload = function() {
       if (xhr.status == 200) {
           let newNblayers = xhr.response;
           if(nblayers !== null && nblayers != newNblayers) {
-              reloadPDF('/signature/'+hash+'/pdf');
+              reloadPDF('/signature/'+pdfHash+'/pdf');
           }
           nblayers = newNblayers;
           document.querySelectorAll('.nblayers').forEach(function(item) {
@@ -1109,7 +1110,8 @@ var pageSignature = async function(url) {
     let pdfBlob = null;
     let filename = url.replace('/pdf/', '');
 
-    if(hash) {
+    if(pdfHash) {
+        storeSymmetricKeyCookie();
         let response = await fetch(url);
         if(response.status != 200) {
             return;
@@ -1141,8 +1143,8 @@ var pageSignature = async function(url) {
     if(sharingMode) {
         setTimeout(function() { runCron() }, 2000);
     }
-    if(hash) {
-        pageSignature('/signature/'+hash+'/pdf');
+    if(pdfHash) {
+        pageSignature('/signature/'+pdfHash+'/pdf');
         window.addEventListener('hashchange', function() {
             window.location.reload();
         })
@@ -1161,4 +1163,8 @@ var pageSignature = async function(url) {
     window.addEventListener('hashchange', function() {
         window.location.reload();
     })
-})();
\ No newline at end of file
+})();
+
+function storeSymmetricKeyCookie() {
+    document.cookie = pdfHash + "=" + window.location.hash + "; SameSite=Strict";
+}
diff --git a/templates/signature.html.php b/templates/signature.html.php
index c44351e..a774d2b 100644
--- a/templates/signature.html.php
+++ b/templates/signature.html.php
@@ -262,10 +262,10 @@
     var maxSize = <?php echo $maxSize ?>;
     var maxPage = <?php echo $maxPage ?>;
     var sharingMode = <?php echo intval(!isset($noSharingMode)) ?>;
-    var hash = null;
+    var pdfHash = null;
     var direction = '<?php echo $DIRECTION_LANGUAGE ?>';
     <?php if(isset($hash)): ?>
-    hash = "<?php echo $hash ?>";
+    pdfHash = "<?php echo $hash ?>";
     <?php endif; ?>
 
     var trad = <?php echo json_encode([