code: private static String createSecureRandom() {
          try {
              final String no = "" + SECURE_RANDOM.nextInt();
              final MessageDigest md = MessageDigest.getInstance("SHA-1");
              final byte[] digest = md.digest(no.getBytes());
              return encodeBase64(digest);
          } catch (final NoSuchAlgorithmException ex) {
              throw new RuntimeException(ex);
          }
      }
docs: Creates a encoded secure random string.
  
  @return Base64 encoded string.