使ajax参数安全

I want to send email value in parameters in ajax. I am using following code it is working properly, but I want to make it secure. no user can check or pass invalid value from calling this action in query string or in any other way. How can I make it secure?

$.ajax({
      url: '/Application/UserInfo/',
      type: 'POST',
      data:{email:emailid},
      success: function (result) {
        var json = eval(result);              
       }
});

If you dont want anyone to be able to see the value of the email parameter, you should consider using HTTPS.

But for passing invalid values, you should do some validation server side where this value is used

It may help if you are doing it with two steps at all:

First you can check the email having the right format with a regular expression:

/^\w[\w|\.\-\_]+@\w[\w\.\-äöüÄÖÜ]+\.[a-zA-Z]{2,18}$/.test(email);

Then you may crypt the mail and then you can send it safely. I am using blowfish. On page loading I generate a key that is set to the javascript of my page. Both, javascript and php have a blowfish controler that can crypt and decrypt any value. I am crypting the value on javascript and send it to the server. There I decrypt it and check it again with regular expression. The key is not sent to server again, its stored somewhere in the session or so.

To take care that the email is correct you can check whether the domain is reachable through curl or so, but I prefer sending a confirmation mail to the adress and wait for an accept with a generated unique token.

If you just want to get sure of a user signed in with google plus account you may get use of the google plus api and check if the user is logged in. If not you don't accept it.