public byte[] verschluessele(String text) {

        try {
            // Verschluesseln
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.ENCRYPT_MODE, this.aesKey);
            byte[] encrypted = cipher.doFinal(text.getBytes());

            return encrypted;
        } catch (NoSuchAlgorithmException ex) {
            Logger.getLogger(Serververbindung.class.getName()).log(Level.SEVERE, null, ex);
        } catch (NoSuchPaddingException ex) {
            Logger.getLogger(Serververbindung.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InvalidKeyException ex) {
            Logger.getLogger(Serververbindung.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IllegalBlockSizeException ex) {
            Logger.getLogger(Serververbindung.class.getName()).log(Level.SEVERE, null, ex);
        } catch (BadPaddingException ex) {
            Logger.getLogger(Serververbindung.class.getName()).log(Level.SEVERE, null, ex);
        }
        return null;
    }