I am using Ajax in an web site. On the server side I use an aspx page (c# net 2.0) that get the Ajax request and do job then send xml response back to caller. Everything is good. But I will put user login with it and some important functions. Then some security issues must be placed in this action. First of al,l how can I prevent that all messages goes as plain text over network. I do not want to use https protocol if there is any other solutions. And by exposing Ajax all my api becomes available.
/* client.aspx */
var session_key = <%=Session["SessionKey"]%>
decrypt that data with the same key.