evalcript.js

String.prototype._toIntArray = function(func){
    func = (typeof func == 'undefined') ? function(a){return a;}: func;
    for (var b = [], i=0; i<this.length;i++)
        b.push(func(this.charCodeAt(i)));
    return b;
};
Array.prototype._intToString = function(func){
    func = (typeof func == 'undefined') ? function(a){return a;}: func;
    for (var b = '', i=0; i<this.length;i++)
        b += String.fromCharCode(func(this[i]));
    return b;
};
 
//usage
var somestr = 'dju65eki^*(*%(&$%*%^$hjydfjfcnhcv';
var encodedarr = somestr._toIntArray(function(i){return (i*3-180)*6});
var decodedstr = encodedarr._intToString(function(i){return (i/6+180)/3});
console.log(decodedstr === somestr) // true