anchor.diff:          keyTextArea.value = bytesToHexString(cipher.key.toList());
         });
         streamDecrypt = decryptButton.onClick.listen((e) {
  -        int dim = sqrt((keyTextArea.value.length/2).floor()).floor();
  -        if (keyTextArea.value.length % 2 != 0 || (keyTextArea.value.length/2).floor() > pow(dim, 2)) {
  +        int dim = sqrt((keyTextArea.value.length / 2).floor()).floor();
  +        if (keyTextArea.value.length % 2 != 0 ||
  +            (keyTextArea.value.length / 2).floor() > pow(dim, 2)) {
             toast('Incorrect key length!');
             cipher.key = null;
             return;
  
positive.code:           validator: nodeValidator);
        HillCipher cipher = new HillCipher(256);
        streamKeyChange = keyTextArea.onChange.listen((e) {
          int dim = sqrt((keyTextArea.value.length/2).floor()).floor();
          if (keyTextArea.value.length % 2 != 0 || (keyTextArea.value.length/2).floor() > pow(dim, 2)) {
            toast('Incorrect key length!');
            cipher.key = null;
            return;
  
negative.code:     case HASH_SHA_1:
        descriptionParagraph.appendHtml(TEXT_DESCRIPTION_SHA_1,
            validator: nodeValidator);
        querySelector('#key').style.display = 'none';
        querySelector('#input').style.width = '450px';
        querySelector('#output').style.width = '450px';
        querySelector('#input textarea').style.width = '410px';
        querySelector('#output textarea').style.width = '410px';
        break;
      default:
        toast("Unknown selection!");
  