后台保存cookies时加密，下面是asp后台的例子：

Function CodeCookie(str)

 Dim strRtn

 For i = Len(str) To 1 step - 1

  strRtn = strRtn & AscW(Mid(str,i,1))

  If (i<>1) Then strRtn = strRtn & "a"

 Next

 CodeCookie = strRtn

End Function

下面是客户端页面读取cookies并解密的js代码：

<script language="JavaScript">

function DecodeCookie(str) {

 var strArr;

 var strRtn="";

 strArr=str.split("a");

 for (var i=strArr.length-1;i>=0;i--)

 strRtn+=String.fromCharCode(eval(strArr[i]));

 return strRtn;

}

function GetCookie(sMainName, sSubName){

 var sCookieName = sMainName + "=";

 var sSubCookieName = (sSubName) ? sSubName + "=" : null;

 var sCookie;

 var sWholeCookie = document.cookie;

 var nValueBegin = sWholeCookie.indexOf(sCookieName);

 if(nValueBegin != -1){

  var nValueEnd = sWholeCookie.indexOf(";", nValueBegin);

  if (nValueEnd == -1) nValueEnd = sWholeCookie.length;

  var sValue = sWholeCookie.substring(nValueBegin + sCookieName.length, nValueEnd);//获得Cookie值

  if(sSubCookieName){//多值Cookie

   var nSubValueBegin = sValue.indexOf(sSubCookieName);

   if(nSubValueBegin != -1){

    var nSubValueEnd = sValue.indexOf("&", nSubValueBegin);

    if(nSubValueEnd == -1) nSubValueEnd = sValue.length;

    var sSubValue = sValue.substring(nSubValueBegin + sSubCookieName.length, nSubValueEnd);//获得指定的子键值

    return unescape(sSubValue);

   }

  }

  if(!sSubCookieName) return unescape(sValue);

 }

 return null;

}

alert(DecodeCookie(GetCookie("MyReg","Stop1")));

</script>