1，

        /**
         * 加解密字符串
         * @author helijun
         * @return {[type]}   [description]
         */
        (function(win) {
            var pwdString = {
                init: function(){
                    var self = pwdString;
                    
                },
                
                options: {
                    defaultPwd: 'helijun'
                },
        
                //加密
                encrypt: function(str, pwd){
                    var self = pwdString;
        
                    if(!str) return '';
        
                    str = encodeURIComponent(str);
        
                    pwd = encodeURIComponent(pwd || self.options.defaultPwd);
        
                    var prand = '';
                    for(var i = 0; i < pwd.length; i ++) {
                        prand += pwd.charCodeAt(i).toString();
                    }
        
                    var sPos = Math.floor(prand.length / 5),
                        mult = parseInt(prand.charAt(sPos) + prand.charAt(sPos * 2) + prand.charAt(sPos * 3) +
                            prand.charAt(sPos * 4) + prand.charAt(sPos * 5)),
                        incr = Math.ceil(pwd.length / 2),
                        modu = Math.pow(2, 31) - 1;
        
                    if(mult < 2) return '';
        
                    var salt = Math.round(Math.random() * 1000000000) % 100000000;
                    prand += salt;   
        
                    while(prand.length > 10) {
                        prand = (parseInt(prand.substring(0, 10)) + 
                                parseInt(prand.substring(10, prand.length))).toString();
                    }
        
                    prand = (mult * prand + incr) % modu;
        
                    var encChr = '',encStr = '';
                    for(var i = 0, len = str.length; i < len; i += 1) {
                        encChr = parseInt(str.charCodeAt(i) ^ Math.floor((prand / modu) * 255));
                        if(encChr < 16) {
                            encStr += '0' + encChr.toString(16);
                        }else{
                            encStr += encChr.toString(16);
                        }
                        prand = (mult * prand + incr) % modu;
                    }  
        
                    salt = salt.toString(16);
                    while(salt.length < 8) {
                        salt = '0' + salt;
                    }
                    encStr += salt;
        
                    return encStr;
                },
                
                //解密
                decrypt: function(str, pwd){
                    var self = pwdString;
        
                    if(str == '') return '';
        
                    pwd = encodeURIComponent(pwd || self.options.defaultPwd);
        
                    if(str == undefined || str.length < 8) {
                        return '';
                    }
                    
                    var prand = '';
                    for(var i = 0; i < pwd.length; i++) {
                        prand += pwd.charCodeAt(i).toString();
                    }
        
                    var sPos = Math.floor(prand.length / 5),
                        mult = parseInt(prand.charAt(sPos) + prand.charAt(sPos * 2) + prand.charAt(sPos * 3) +
                            prand.charAt(sPos * 4) + prand.charAt(sPos * 5)),
                        incr = Math.round(pwd.length / 2),
                        modu = Math.pow(2, 31) - 1,
                        salt = parseInt(str.substring(str.length - 8, str.length), 16);
        
                    str = str.substring(0, str.length - 8);
                    prand += salt;
        
                    while(prand.length > 10) {
                        prand = (parseInt(prand.substring(0, 10)) + 
                                parseInt(prand.substring(10, prand.length))).toString();   
                    }
                    prand = (mult * prand + incr) % modu;
                    
                    var encChr = '',encStr = '';
                    for(var i = 0, len = str.length; i < len; i += 2) {
                        encChr = parseInt(parseInt(str.substring(i, i + 2), 16) ^ Math.floor((prand / modu) * 255));   
                        encStr += String.fromCharCode(encChr);   
                        prand = (mult * prand + incr) % modu;   
                    }
        
                    return decodeURIComponent(encStr);
                },
                
                render: function(){
                    var self = pwdString;
                }
            }
            
            win.pwdString = pwdString;
        })(window);


        // console.log(window.pwdString.encrypt("easyshow"));

        var str1 = window.pwdString.encrypt("easyshow");
        var str2 = window.pwdString.decrypt(str1);

        console.log(str1);
        console.log(str2);