diff --git a/src/OpenIDConnectClient.php b/src/OpenIDConnectClient.php
index ee81b02c..2568b44a 100644
--- a/src/OpenIDConnectClient.php
+++ b/src/OpenIDConnectClient.php
@@ -307,6 +307,11 @@ public function authenticate() {
                 throw new OpenIDConnectClientException('Got response: ' . $token_json->error);
             }
 
+            // Sometime getState() return an empty string
+            // and the authentication process fail
+            if ($this->getState() == "")
+                $this->setState($_REQUEST['state']);
+            
             // Do an OpenID Connect session check
             if ($_REQUEST['state'] !== $this->getState()) {
                 throw new OpenIDConnectClientException('Unable to determine state');
@@ -339,6 +344,13 @@ public function authenticate() {
             // Save the access token
             $this->accessToken = $token_json->access_token;
 
+            // During verifyJWTclaims sometime return an empty string (probably caused by the session timeout between KC and Client)
+            // Which cause issue in the *_auth.php, this should "patch" the randomic emptiness.
+            if ($this->getNonce() == "") {
+                $this->setNonce($claims->nonce);
+                user_error('Warning: Function getNonce return empty, setting in the session!');
+            };
+            
             // If this is a valid claim
             if ($this->verifyJWTclaims($claims, $token_json->access_token)) {
 
@@ -430,27 +442,32 @@ public function authenticate() {
      * Connect provider that the end-user has logged out of the relying party site
      * (the client application).
      *
-     * @param string $accessToken ID token (obtained at login)
+     * @param string $enduserIdentification ID token (obtained at login) or username for $method like as "login_hint"
      * @param string|null $redirect URL to which the RP is requesting that the End-User's User Agent
      * be redirected after a logout has been performed. The value MUST have been previously
      * registered with the OP. Value can be null.
+     * @param string $method The way of identifying the end-user for whom authentication is being requested.
+     * The default setting is "id_token_hint". There are two modes supported: "login_hint" and "id_token_hint"
      *
      * @throws OpenIDConnectClientException
      */
-    public function signOut($accessToken, $redirect) {
-        $signout_endpoint = $this->getProviderConfigValue('end_session_endpoint');
+    public function signOut($enduserIdentification, $redirect, $method = "id_token_hint") {
+        if (!in_array($method, array("id_token_hint", "login_hint")))
+            throw new OpenIDConnectClientException('method must be "id_token_hint" or "login_hint"');
+
+        $signout_endpoint = $this->getProviderConfigValue("end_session_endpoint");
 
         $signout_params = null;
         if($redirect === null){
-            $signout_params = array('id_token_hint' => $accessToken);
+            $signout_params = array($method => $enduserIdentification);
         }
         else {
             $signout_params = array(
-                'id_token_hint' => $accessToken,
+                $method => $enduserIdentification,
                 'post_logout_redirect_uri' => $redirect);
         }
 
-        $signout_endpoint  .= (strpos($signout_endpoint, '?') === false ? '?' : '&') . http_build_query( $signout_params, null, '&', $this->enc_type);
+        $signout_endpoint  .= (strpos($signout_endpoint, '?') === false ? '?' : '&') . http_build_query( $signout_params, '', '&', $this->enc_type);
         $this->redirect($signout_endpoint);
     }
 
@@ -675,7 +692,7 @@ private function requestAuthorization() {
             ));
         }
 
-        $auth_endpoint .= (strpos($auth_endpoint, '?') === false ? '?' : '&') . http_build_query($auth_params, null, '&', $this->enc_type);
+        $auth_endpoint .= (strpos($auth_endpoint, '?') === false ? '?' : '&') . http_build_query($auth_params, '', '&', $this->enc_type);
 
         $this->commitSession();
         $this->redirect($auth_endpoint);
@@ -701,7 +718,7 @@ public function requestClientCredentialsToken() {
         );
 
         // Convert token params to string format
-        $post_params = http_build_query($post_data, null, '&', $this->enc_type);
+        $post_params = http_build_query($post_data, '', '&', $this->enc_type);
 
         return json_decode($this->fetchURL($token_endpoint, $post_params, $headers));
     }
@@ -736,7 +753,7 @@ public function requestResourceOwnerToken($bClientAuth =  FALSE) {
         }
 
         // Convert token params to string format
-        $post_params = http_build_query($post_data, null, '&', $this->enc_type);
+        $post_params = http_build_query($post_data, '', '&', $this->enc_type);
 
         return json_decode($this->fetchURL($token_endpoint, $post_params, $headers));
     }
@@ -782,7 +799,7 @@ protected function requestTokens($code) {
         }
 
         // Convert token params to string format
-        $token_params = http_build_query($token_params, null, '&', $this->enc_type);
+        $token_params = http_build_query($token_params, '', '&', $this->enc_type);
 
         $this->tokenResponse = json_decode($this->fetchURL($token_endpoint, $token_params, $headers));
 
@@ -809,7 +826,7 @@ public function refreshToken($refresh_token) {
         );
 
         // Convert token params to string format
-        $token_params = http_build_query($token_params, null, '&', $this->enc_type);
+        $token_params = http_build_query($token_params, '', '&', $this->enc_type);
 
         $json = json_decode($this->fetchURL($token_endpoint, $token_params));
 
@@ -1424,7 +1441,7 @@ public function introspectToken($token, $token_type_hint = '', $clientId = null,
         $clientSecret = $clientSecret !== null ? $clientSecret : $this->clientSecret;
 
         // Convert token params to string format
-        $post_params = http_build_query($post_data, null, '&');
+        $post_params = http_build_query($post_data, '', '&');
         $headers = ['Authorization: Basic ' . base64_encode(urlencode($clientId) . ':' . urlencode($clientSecret)),
             'Accept: application/json'];
 
@@ -1455,7 +1472,7 @@ public function revokeToken($token, $token_type_hint = '', $clientId = null, $cl
         $clientSecret = $clientSecret !== null ? $clientSecret : $this->clientSecret;
 
         // Convert token params to string format
-        $post_params = http_build_query($post_data, null, '&');
+        $post_params = http_build_query($post_data, '', '&');
         $headers = ['Authorization: Basic ' . base64_encode(urlencode($clientId) . ':' . urlencode($clientSecret)),
             'Accept: application/json'];