javascript混淆加密

源代码：<textarea id="ta" style="width:100%;height:300px">alert('大家好，我是showbo!𠮷双字节测试')</textarea>
<input type="button" value="加密" onclick=" taEncrypt.value = encrypSource(ta.value);" />　<input type="button" value="执行加密代码" onclick="eval(taEncrypt.value)" /><br />
加密后代码：<textarea id="taEncrypt" style="width:100%;height:300px">
</textarea>
<script>
    var kv = { "0": "___", "1": "__$", "2": "_$_", "3": "_$$", "4": "$__", "5": "$_$", "6": "$$_", "7": "$$$", "8": "$___", "9": "$__$", "f": "$$$$", "a": "$_$_", "b": "$_$$", "d": "$$_$", "e": "$$$_", "c": "$$__", "o": "_$", "t": "__", "u": "_" };
    function getOctalStr(c) {
        var s = '+"\\\\"';
        var sOctal = c.charCodeAt(0).toString(8);
        for (var i = 0; i < sOctal.length; i++) s += '+$.' + kv[sOctal.charAt(i)];
        return s;
    }
    function padding(s, l, c) { if (s.length < l) for (var i = l - s.length; i > 0; i--) s = c + s; return s;}
    function encrypSource(s) {
        //////处理大于255 ASCII字符为16进制编码
        s = s.replace(/[\u0100-\uFFFF]+/g, function (s) {
            var r = '';
            for (var i = 0; i < s.length; i++) r += '\\u' + padding(s.charCodeAt(i).toString(16), 4, 0);
            return r;
        });
        ////////

        var r = '';
        //将s转为8进制表示
        for (var i = 0, l = s.length; i < l; i++) {
            var c = s.charAt(i);
            if (kv[c]) {//不需要转8进制的字符
                r += '+$.' + kv[c];
            }
            else {//字符转8进制
                r += getOctalStr(c);
            }
        }
        //加上原文网站解码程序
        return '$=~[];$={___:++$,$$$$:(![]+"")[$],__$:++$,$_$_:(![]+"")[$],_$_:++$,$_$$:({}+"")[$],$$_$:($[$]+"")[$],_$$:++$,$$$_:(!""+"")[$],$__:++$,$_$:++$,$$__:({}+"")[$],$$_:++$,$$$:++$,$___:++$,$__$:++$};$.$_=($.$_=$+"")'
        + '[$.$_$]+($._$=$.$_[$.__$])+($.$$=($.$+"")[$.__$])+((!$)+"")[$._$$]+($.__=$.$_[$.$$_])+($.$=(!""+"")[$.__$])+($._=(!""+"")[$._$_])+$.$_[$.$_$]+$.__'
        + '+$._$+$.$;$.$$=$.$+(!""+"")[$._$$]+$.__+$._+$.$+$.$$;$.$=($.___)[$.$_][$.$_];$.$($.$(' +

        '$.$$+"\\""' + r + '+"\\""'//这串是加密后的

        + ')())();'
        ;
    }
   
</script>