diff --git a/src/Authentication/JsonWebToken.php b/src/Authentication/JsonWebToken.php
index aacdbe7..454cb8e 100644
--- a/src/Authentication/JsonWebToken.php
+++ b/src/Authentication/JsonWebToken.php
@@ -191,8 +191,9 @@ public function decode($token, $key = null)
 
                 return false;
             }
+            
             // Check if this token has expired.
-            if (isset($payload->exp) && ($timestamp - $this->leeway) >= $payload->exp) {
+            if (isset($payload->exp) && ($timestamp - $this->leeway) >= strtotime($payload->exp)) {
                 $this->errors[] = 'Expired token';
 
                 return false;
diff --git a/src/Authentication/User.php b/src/Authentication/User.php
index 6abaeed..34f698a 100644
--- a/src/Authentication/User.php
+++ b/src/Authentication/User.php
@@ -16,6 +16,7 @@
 // ------------------------------------------------------------------------
 
 use O2System\Cache\Item;
+use O2System\Spl\DataStructures\SplArrayObject;
 use O2System\Spl\Traits\Collectors\ConfigCollectorTrait;
 use Psr\Cache\CacheItemPoolInterface;
 
@@ -35,13 +36,13 @@ class User
     public function __construct()
     {
         $this->setConfig([
-            'password'    => [
+            'password' => [
                 'algorithm' => PASSWORD_DEFAULT,
-                'options'   => [],
+                'options' => [],
             ],
             'msisdnRegex' => '/^\+[1-9]{1}[0-9]{3,14}$/',
             'maxAttempts' => 5,
-            'sso'         => [
+            'sso' => [
                 'enable' => false,
                 'server' => base_url(),
             ],
@@ -95,8 +96,8 @@ public function passwordRehash($password)
     {
         if (password_needs_rehash(
             $password,
-            $this->config[ 'password' ][ 'algorithm' ],
-            $this->config[ 'password' ][ 'options' ]
+            $this->config['password']['algorithm'],
+            $this->config['password']['options']
         )) {
             return $this->passwordHash($password);
         }
@@ -117,8 +118,8 @@ public function passwordHash($password)
     {
         return password_hash(
             $password,
-            $this->config[ 'password' ][ 'algorithm' ],
-            $this->config[ 'password' ][ 'options' ]
+            $this->config['password']['algorithm'],
+            $this->config['password']['options']
         );
     }
 
@@ -144,7 +145,7 @@ public function passwordVerify($password, $hash)
      */
     public function attempt()
     {
-        $_SESSION[ 'userAttempts' ] = $this->getAttempts() + 1;
+        $_SESSION['userAttempts'] = $this->getAttempts() + 1;
     }
 
     // ------------------------------------------------------------------------
@@ -157,8 +158,8 @@ public function attempt()
     public function getAttempts()
     {
         $currentAttempts = 0;
-        if (isset($_SESSION[ 'userAttempts' ])) {
-            $currentAttempts = (int)$_SESSION[ 'userAttempts' ];
+        if (isset($_SESSION['userAttempts'])) {
+            $currentAttempts = (int)$_SESSION['userAttempts'];
         }
 
         return (int)$currentAttempts;
@@ -166,55 +167,6 @@ public function getAttempts()
 
     // ------------------------------------------------------------------------
 
-    /**
-     * User::login
-     *
-     * @param array $account
-     */
-    public function login(array $account)
-    {
-        $_SESSION[ 'account' ] = $account;
-        unset($_SESSION[ 'userAttempts' ]);
-    }
-
-    // ------------------------------------------------------------------------
-
-    /**
-     * User::signOn
-     *
-     * @param array $account
-     *
-     * @throws \Exception
-     */
-    public function signOn(array $account)
-    {
-        $cacheItemPool = $this->getCacheItemPool();
-        $virtualUserId = md5(json_encode($account) . mt_srand() . time());
-        $cacheItemPool->save(new Item('sso-' . $virtualUserId, $account, false));
-
-        set_cookie('ssid', $virtualUserId);
-    }
-
-    // ------------------------------------------------------------------------
-
-    /**
-     * User::getCacheItemPool
-     *
-     * @return CacheItemPoolInterface
-     */
-    protected function getCacheItemPool()
-    {
-        $cacheItemPool = cache()->getObject('default');
-
-        if (cache()->exists('sso')) {
-            $cacheItemPool = cache()->getObject('sso');
-        }
-
-        return $cacheItemPool;
-    }
-
-    // ------------------------------------------------------------------------
-
     /**
      * User::loggedIn
      *
@@ -223,11 +175,7 @@ protected function getCacheItemPool()
      */
     public function loggedIn()
     {
-        if (isset($_SESSION[ 'account' ])) {
-            return true;
-        } elseif($this->tokenOn()) {
-            return true;
-        } elseif ($this->signedOn()) {
+        if (isset($_SESSION['account'])) {
             return true;
         }
 
@@ -237,46 +185,13 @@ public function loggedIn()
     // ------------------------------------------------------------------------
 
     /**
-     * User::tokenOn
-     */
-    public function tokenOn()
-    {
-        if(false !== ($token = input()->bearerToken())) {
-            $_SESSION['account'] = (new JsonWebToken())->decode($token);
-
-            globals()->store('account', $_SESSION['account']);
-
-            return true;
-        }
-
-        return false;
-    }
-
-    // ------------------------------------------------------------------------
-
-    /**
-     * User::signedOn
+     * AccessControl::login
      *
-     * @return bool
-     * @throws \Psr\Cache\InvalidArgumentException
+     * @param array $account
      */
-    public function signedOn()
+    public function login(array $account)
     {
-        if ($virtualUserId = input()->cookie('ssid')) {
-            $cacheItemPool = $this->getCacheItemPool();
-
-            if($cacheItemPool->hasItem('sso-' . $virtualUserId)) {
-
-                $item = $cacheItemPool->getItem('sso-' . input()->cookie('ssid'));
-                $_SESSION['account'] = $item->get();
-
-                globals()->store('account', $_SESSION['account']);
-
-                return true;
-            }
-        }
-
-        return false;
+        $_SESSION['account'] = $account;
     }
 
     // ------------------------------------------------------------------------
@@ -286,26 +201,8 @@ public function signedOn()
      */
     public function logout()
     {
-        $this->signOff();
-
-        if (isset($_SESSION[ 'account' ])) {
-            unset($_SESSION[ 'account' ]);
-        }
-    }
-
-    // ------------------------------------------------------------------------
-
-    /**
-     * User::signOff
-     *
-     * @throws \Psr\Cache\InvalidArgumentException
-     */
-    public function signOff()
-    {
-        if ($virtualUserId = input()->cookie('ssid')) {
-            $cacheItemPool = $this->getCacheItemPool();
-            $cacheItemPool->deleteItem('sso-' . $virtualUserId);
-            delete_cookie('ssid');
+        if (isset($_SESSION['account'])) {
+            unset($_SESSION['account']);
         }
     }
 }
\ No newline at end of file
diff --git a/src/Encryptions/Binary.php b/src/Encryptions/Binary.php
index 294bb01..d032985 100644
--- a/src/Encryptions/Binary.php
+++ b/src/Encryptions/Binary.php
@@ -28,6 +28,7 @@ class Binary
      * @var array
      */
     private static $charactersMap = [];
+    
     /**
      * Binary::$crypt
      *
diff --git a/src/Encryptions/Hexadecimal.php b/src/Encryptions/Hexadecimal.php
new file mode 100644
index 0000000..35d71ef
--- /dev/null
+++ b/src/Encryptions/Hexadecimal.php
@@ -0,0 +1,106 @@
+<?php
+/**
+ * This file is part of the O2System Framework package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @author         Steeve Andrian Salim
+ * @copyright      Copyright (c) Steeve Andrian Salim
+ */
+
+// ------------------------------------------------------------------------
+
+namespace O2System\Security\Encryptions;
+
+// ------------------------------------------------------------------------
+
+/**
+ * Class Hexadecimal
+ * @package O2System\Security\Encryptions
+ */
+class Hexadecimal
+{
+    /**
+     * Binary::$crypt
+     *
+     * Crypt instance.
+     *
+     * @var Crypt
+     */
+    private $crypt;
+
+    // ------------------------------------------------------------------------
+
+    /**
+     * Binary::__construct
+     */
+    public function __construct()
+    {
+        $this->crypt = new Crypt();
+    }
+
+    // ------------------------------------------------------------------------
+
+    /**
+     * Hexadecimal::encrypt
+     *
+     * Encrypt string into numbers.
+     *
+     * @param string $string String to be encrypted.
+     *
+     * @return string
+     */
+    public function encrypt($string)
+    {
+        $dec = [];
+        $hex = str_split($this->crypt->encrypt($string), 4);
+        
+        foreach ($hex as $char) {
+            $dec[] = str_pad(hexdec($char), 5, '0', STR_PAD_LEFT);
+        }
+        
+        return implode('', $dec);
+    }
+
+    // ------------------------------------------------------------------------
+
+    /**
+     * Hexadecimal::decrypt
+     *
+     * Decrypt numbers.
+     *
+     * @param string $string String to be decrypted.
+     *
+     * @return string
+     */
+    public function decrypt($string)
+    {
+        $hex = [];
+        $dec = str_split($string, 5);
+
+        foreach ($dec as $char) {
+            $hex[] = str_pad(dechex($char), 4, '0', STR_PAD_LEFT);
+        }
+
+        return implode('', $hex);
+    }
+
+    // ------------------------------------------------------------------------
+
+    /**
+     * Hexadecimal::setKey
+     *
+     * Sets numeric encryption protection key.
+     *
+     * @param string $key Custom encryption key.
+     *
+     * @return static
+     */
+    public function setKey($key)
+    {
+        $this->crypt->setKey($key);
+
+        return $this;
+    }
+}
\ No newline at end of file
diff --git a/src/Form/Validator.php b/src/Form/Validator.php
index fee4a75..17fb5d8 100644
--- a/src/Form/Validator.php
+++ b/src/Form/Validator.php
@@ -360,12 +360,14 @@ protected function processRules(string $field, string $label = null, $value, $ru
 
             if ( ! $callable && preg_match('/(.*?)\[(.*)\]/', $rule, $match)) {
                 $rule = $match[ 1 ];
-                $params = $match[ 2 ];
+                if (is_array($match[ 2 ])) {
+                    $params = array_merge([$value], $match[ 2 ]);
+                } else {
+                    $params = [$value, $match[ 2 ]];
+                }
             }
 
-            if ($params) {
-                $params = array_merge([$value], $params);
-            } else {
+            if (empty($params)) {
                 $params = [$value];
             }
 
@@ -384,8 +386,7 @@ protected function processRules(string $field, string $label = null, $value, $ru
                     $error = $this->customErrors[ $field ][ $rule ];
                 }
 
-                $this->errors[ $field ] = is_null($error) ? $this->getErrorMessage($rule, $field, $label,
-                    $params) : $error;
+                $this->errors[ $field ] = is_null($error) ? $this->getErrorMessage($rule, $field, $label, $value) : $error;
 
                 return false;
             }
@@ -443,11 +444,11 @@ public function getError(string $field = null): string
      * @param string      $rule
      * @param string      $field
      * @param string|null $label
-     * @param string      $param
+     * @param string      $value
      *
      * @return string
      */
-    protected function getErrorMessage(string $rule, string $field, string $label = null, string $param = null): string
+    protected function getErrorMessage(string $rule, string $field, string $label = null, string $value = null): string
     {
         // Check if custom message has been defined by user
         if (isset($this->customErrors[ $field ][ $rule ])) {
@@ -460,7 +461,7 @@ protected function getErrorMessage(string $rule, string $field, string $label =
         }
 
         $message = str_replace('{field}', $label ?? $field, $message);
-        $message = str_replace('{param}', $this->rules[ $param ][ 'label' ] ?? $param, $message);
+        $message = str_replace('{value}', $value ?? null, $message);
 
         return $message;
     }