title: SSO between two websites in different platforms
body: <p>I have a requirement where I need to implement SSO between two different websites.</p>
  
  <p>One of the website say www.abc.com is written using ASP.NET and is hosted on IIS 7.0. The second website say www.xyz.com is written using PHP and uses Apache web server. Both the websites uses different databases and uses different algorithms to authenticate the user.</p>
  
  <p>I cannot use a third party SSO as that would mean changing the authentication for both the websites. Wanted to know if this is possible and if yes, what should be the approach?</p>
  
  <p>Thanks in advance...</p>