diff --git a/app.php b/app.php
index d3f7351..7498ef7 100644
--- a/app.php
+++ b/app.php
@@ -230,8 +230,7 @@ $f3->route('POST /share',
                     return basename($tmpfile."_".$fileBaseName);
                 }
 	    });
-        array_map('cryptographyClass::hardUnlink', $_FILES['svg']['tmp_name']);
-        CryptographyClass::hardUnlink($_FILES['pdf']['tmp_name']);
+
         if(!count($files)) {
             $f3->error(403);
         }
@@ -241,15 +240,14 @@ $f3->route('POST /share',
         if(!$f3->get('DEBUG')) {
             array_map('cryptographyClass::hardUnlink', glob($tmpfile."*.svg"));
         }
-        if (!isset($_COOKIE[$hash])) {
-            $symmetric_key = createSymmetricKey();
-            $keyCookieDate = strtotime('+1 year');
-            setcookie($hash, $symmetric_key, ['expires' => $keyCookieDate, 'samesite' => 'Strict', 'path' => "/"]);
-        }
-        $encryptor = new CryptographyClass($symmetric_key);
-        $encryptor->encrypt($hash);
+        $symmetricKey = CryptographyClass::createSymmetricKey();
+        setcookie($hash, $symmetricKey, ['expires' => 0, 'samesite' => 'Strict', 'path' => "/"]);
 
-        $f3->reroute($f3->get('REVERSE_PROXY_URL').'/signature/'.$hash."#sk:".$symmetric_key);
+        $encryptor = new CryptographyClass($symmetricKey, $f3->get('PDF_STORAGE_PATH').$hash);
+        $encryptor->encrypt();
+
+
+        $f3->reroute($f3->get('REVERSE_PROXY_URL').'/signature/'.$hash."#sk:".$symmetricKey);
     }
 
 );
@@ -260,12 +258,11 @@ $f3->route('GET /signature/@hash/pdf',
         $hash = Web::instance()->slug($f3->get('PARAMS.hash'));
         $sharingFolder = $f3->get('PDF_STORAGE_PATH').$hash;
 
-        if (substr($_COOKIE[$hash], 0, 4) !== '#sk:') {
-            echo "Error: Invalid prefix.";
-            exit;
+        if (CryptographyClass::isSymmetricKeyValid($_COOKIE[$hash]) == false) {
+            $f3->error(403);
         }
-        $cryptor = new CryptographyClass(substr($_COOKIE[$hash], 4, 15));
-        $cryptor->decrypt($hash);
+        $cryptor = new CryptographyClass($_COOKIE[$hash], $f3->get('PDF_STORAGE_PATH').$hash);
+        $cryptor->decrypt();
 
         $files = scandir($sharingFolder);
         $originalFile = $sharingFolder.'/original.pdf';
@@ -536,15 +533,4 @@ function convertPHPSizeToBytes($sSize)
     return (int)$iValue;
 }
 
-function createSymmetricKey() {
-        $length = 15;
-        $keyspace = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
-        $pieces = [];
-        $max = mb_strlen($keyspace, '8bit') - 1;
-        for ($i = 0; $i < $length; ++$i) {
-            $pieces []= $keyspace[random_int(0, $max)];
-        }
-        return implode('', $pieces);
-    }
-
 return $f3;
diff --git a/lib/cryptography.class.php b/lib/cryptography.class.php
index 22d53aa..395c5ee 100644
--- a/lib/cryptography.class.php
+++ b/lib/cryptography.class.php
@@ -2,54 +2,77 @@
 
 class CryptographyClass
 {
-    private $symmetric_key = null;
+    private $symmetricKey = null;
+    private $pathHash = null;
 
-    function __construct($key) {
-            $this->setSymmetricKey($key);
+    function __construct($key, $pathHash) {
+            $this->symmetricKey = $key;
+            $this->pathHash = $pathHash;
     }
 
-    public function encrypt($hash) {
-        foreach (glob("/tmp/".$hash.'/*.pdf') as $file) {
+    private function getFiles($isGpg) {
+        $suffix = "";
+        if ($isGpg) {
+            $suffix = ".gpg";
+        }
+        $filesTab = glob($this->pathHash.'/*.pdf'.$suffix);
+        $filesTab[] = $this->pathHash."/filename.txt".$suffix;
+
+        return $filesTab;
+    }
+
+    public function encrypt() {
+
+        foreach ($this->getFiles(false) as $file) {
             $outputFile = $file.".gpg";
-            $key = $this->getSymmetricKey();
-            $command = "gpg --batch --passphrase $key --symmetric --cipher-algo AES256 -o $outputFile $file";
+            $command = "gpg --batch --passphrase $this->symmetricKey --symmetric --cipher-algo AES256 -o $outputFile $file";
             $result = shell_exec($command);
             if ($result === false) {
                 echo "Cypher failure";
                 exit;
             }
-            unlink($file);
+            $this->hardUnlink($file);
         }
     }
 
-    public function decrypt($hash) {
-        foreach (glob("/tmp/".$hash.'/*.gpg') as $file) {
+    public function decrypt() {
+        foreach ($this->getFiles(true) as $file) {
             $outputFile = str_replace(".gpg", "", $file);
-            $key = $this->getSymmetricKey();
-            $command = "gpg --batch --passphrase $key --decrypt -o $outputFile $file";
+            $command = "gpg --batch --passphrase $this->symmetricKey --decrypt -o $outputFile $file";
             $result = shell_exec($command);
             if ($result === false) {
                 echo "Decypher failure";
                 exit;
             }
-            unlink($file);
+            $this->hardUnlink($file);
         }
         return true;
     }
 
-    private function getSymmetricKey() {
-        return $this->symmetric_key;
-    }
-
-    private function setSymmetricKey($key) {
-        $this->symmetric_key = $key;
-    }
-
     public static function hardUnlink($element) {
-        $eraser = str_repeat(0, strlen($element));
+        if (!$element) {
+            return;
+        }
+        print_r(['hu', $element]);
+        $eraser = str_repeat(0, strlen(file_get_contents($element)));
         file_put_contents($element, $eraser);
         unlink($element);
     }
 
+    public static function isSymmetricKeyValid($key) {
+        return (bool)preg_match('/^[0-9a-zA-Z]{15}$/', $key);
+    }
+
+    public static function createSymmetricKey() {
+            $length = 15;
+            $keySpace = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
+            $pieces = [];
+            $max = mb_strlen($keySpace, '8bit') - 1;
+            for ($i = 0; $i < $length; ++$i) {
+                $pieces []= $keySpace[random_int(0, $max)];
+            }
+
+            return implode('', $pieces);
+        }
 }
 ?>
diff --git a/public/js/signature.js b/public/js/signature.js
index b6ef42b..165bb5a 100644
--- a/public/js/signature.js
+++ b/public/js/signature.js
@@ -1166,5 +1166,12 @@ var pageSignature = async function(url) {
 })();
 
 function storeSymmetricKeyCookie() {
-    document.cookie = pdfHash + "=" + window.location.hash + "; SameSite=Strict";
+    let symmetricKey = window.location.hash;
+    if (symmetricKey.length != 19) {
+        console.error("Erreur taille cle symmetrique.");
+        return;
+    } else if (symmetricKey.substr(0, 4) != "#sk:") {
+        console.error("Erreur format cle symmetrique");
+    }
+    document.cookie = pdfHash + "=" + symmetricKey.substr(4, 15) + "; SameSite=Strict";
 }