diff --git a/gateways/gateway.php b/gateways/gateway.php
index d55313e..6cdacfb 100644
--- a/gateways/gateway.php
+++ b/gateways/gateway.php
@@ -204,7 +204,7 @@ public function getCurrency() {
    */
   public function checkFields(array $fields) {
   	foreach ($fields as $k => $v) {
-  	  if (empty($v)) {
+  	  if (!isset($v) || $v == "") {
   	  	return FALSE;
   	  }
   	}
diff --git a/gateways/luottokunta.php b/gateways/luottokunta.php
index 6242c7e..131c2b2 100644
--- a/gateways/luottokunta.php
+++ b/gateways/luottokunta.php
@@ -1,99 +1,139 @@
 <?php
+
 /**
  * Gateway for Luottokunta
  * 
- * UNTESTED
+ * Refactored gateway to be compatible with the new rules of Luottokunta
+ * Uses hash('sha256', $mac) instead of md5($mac) which is the new infosec-policy
  *
  */
-
 class FpiapiGatewayLuottokunta extends FpiapiGateway {
-  
-
-  /**
-   * Constructor
-   */
-  public function __construct() {
-    parent::__construct();
-    $this->name = "Luottokunta";
-    $this->postUrl = 'https://dmp2.luottokunta.fi/dmp/html_payments';
-    $this->hasPaymentAbility = true;
-  }
-  
-  /**
-   * getPaymentFields()
-   * @see fpiapi/gateways/FpiapiGateway::getPaymentFields()
-   */
-  public function getPaymentFields() {
-    
-    // First fill in the field used to calculate mac
-    $fields = array(
-      'Merchant_Number'  => $this->configuration['publicKey'],
-      'Order_ID'         => $this->transaction->getUid(),
-      'Amount'           => round($this->transaction->getSum()*100),
-      'Transaction_Type' => '1'
-    );
-    
-    // Calculate mac
-    $mac = implode('', $fields) . $this->configuration['privateKey'];
-    $mac = strtolower(md5($mac));
-    
-    // Convert currency to numeric code
-    switch($this->getCurrency()) {
-      case 'EUR': 
-        $currency = 978;
-        break;
+
+    /**
+     * Constructor
+     */
+    public function __construct() {
+        parent::__construct();
+        $this->name = "Luottokunta";
+        $this->postUrl = 'https://dmp2.luottokunta.fi/dmp/html_payments';
+        $this->hasPaymentAbility = true;
+    }
+
+    /**
+     * getPaymentFields()
+     * @see fpiapi/gateways/FpiapiGateway::getPaymentFields()
+     */
+    public function getPaymentFields() {
+
+        $mac_fields = $this->getFieldArrayForRequest();
+
+        $mac_str = implode("&", $mac_fields);
+        $mac = hash('sha256', $mac_str);
+
+        $fields = array(
+            'Authentication_Mac'     => $mac,
+            'Success_Url'            => $this->getReturnUrl(),
+            'Failure_Url'            => $this->getErrorUrl(),
+            'Cancel_Url'             => $this->getErrorUrl(),
+            'Device_Category'        => $this->getDeviceCategory(),
+            'Card_Details_Transmit'  => $this->getCardDetailsTransmit(),
+            'Currency_Code'          => $this->getCurrencyCode(),
+            'Merchant_Number'        => $this->configuration['publicKey'],
+            'Order_ID'               => $this->transaction->getUid(),
+            'Amount'                 => $this->getFormattedSum(),
+            'Transaction_Type'       => $this->getTransactionType(),
+        );
+
+        return $fields;
     }
-    
-    $fields['Authentication_Mac']    = $mac;
-    $fields['Success_Url']           = $this->getReturnUrl();
-    $fields['Failure_Url']           = 
-    $fields['Cancel_Url']            = $this->getErrorUrl();
-    $fields['Device_Category']       = '1';
-    $fields['Card_Details_Transmit'] = '0'; // Ask card details at the other end
-    $fields['Currency_Code']         = $currency;
-   
-
-    return $fields;
-  }
-  
-  
-  /**
-   * isPaymentCompleted()
-   * @see fpiapi/gateways/FpiapiGateway::isPaymentCompleted()
-   */
-  public function isPaymentCompleted() {
-    
-    $params = &$_REQUEST;
-    
-    if (!isset($params['LKMAC']))
-      return false;
-
-    if (!isset($params['LKPRC']))
-      return false;
-      
-    // First fill in the field used to calculate mac
-    $fields = array(
-      'Merchant_Number'  => $this->configuration['publicKey'],
-      'Order_ID'         => $this->transaction->getUid(),
-      'Amount'           => $this->transaction->getSum(),
-      'Transaction_Type' => '1'
-    );
-    
-    if (!$this->checkFields($fields)) {
-      return false;
+
+    /**
+     * isPaymentCompleted()
+     * @see fpiapi/gateways/FpiapiGateway::isPaymentCompleted()
+     */
+    public function isPaymentCompleted() {
+
+        $params = &$_REQUEST;
+
+        if (!isset($params['LKMAC'])) {
+            return false;
+        }
+
+        $fields = $this->getFieldArrayForResponse();
+
+        if (!$this->checkFields($fields)) {
+            return false;
+        }
+
+        $mac_str = implode("&", $fields);
+        $mac     = hash('sha256', $mac_str);
+
+        return strtolower($mac) == strtolower($params['LKMAC']);
     }
-    
-    // reverse array to calculate return mac
-    $fields = array_reverse($fields);
-    
-    // Calculate mac
-    $mac = implode('', $fields) . $this->configuration['privateKey'];
-    $mac = strtolower(md5($mac));
-    
-    return $mac == $params['LKMAC'];
-
-  }
-  
-  
-
-}
+
+    protected function getFieldArrayForResponse() {
+
+        $fields = array(
+            'Private_key'      => $this->configuration['privateKey'],
+            'Transaction_Type' => $this->getTransactionType(),
+            'Currency_Code'    => $this->getCurrencyCode(),
+            'Amount'           => $this->getFormattedSum(),
+            'Order_ID'         => $this->transaction->getUid(),
+            'Merchant_Number'  => $this->configuration['publicKey'],
+        );
+
+        $LB_fields = array(
+            'LKBINCOUNTRY',
+            'LKIPCOUNTRY',
+            'LKECI',
+        );
+
+        // Add LB-fields if they exist in reponse
+        foreach ($LB_fields as $LB_field) {
+            if (isset($_REQUEST[$LB_field])) {
+                $fields[$LB_field] = $_REQUEST[$LB_field];
+            }
+        }
+
+        return $fields;
+    }
+
+    protected function getFieldArrayForRequest() {
+
+        $fields = array(
+            'Merchant_Number'  => $this->configuration['publicKey'], 
+            'Order_ID'         => $this->transaction->getUid(),            
+            'Amount'           => $this->getFormattedSum(),
+            'Currency_Code'    => $this->getCurrencyCode(),
+            'Transaction_Type' => $this->getTransactionType(),
+            'Private_key'      => $this->configuration['privateKey'],
+        );
+
+        return $fields;
+    }
+
+    protected function getFilteredSum() {
+        return str_replace(",", ".", $this->transaction->getSum());
+    }
+
+    protected function getFormattedSum() {
+        return round($this->getFilteredSum() * 100);
+    }
+
+    protected function getTransactionType() {
+        return '1';
+    }
+
+    protected function getCurrencyCode() {
+        return '978';
+    }
+
+    protected function getDeviceCategory() {
+        return '1';
+    }
+
+    protected function getCardDetailsTransmit() {
+        return '0';
+    }
+
+}
\ No newline at end of file