SharePoint Foundation 2010 supports authentication methods that were included in previous versions and also introduces token-based authentication that is based on Security Assertion Markup Language (SAML) as an option. The following table lists the supported authentication methods.
Application that support Windows integrated authentication (NTLM or Kerberos, as described in http://spnego.sourceforge.net/
For more, please review http://msdn.microsoft.com/en-us/magazine/ff872350.aspx andhttp://www.codeproject.com/Articles/106439/Single-Sign-On-SSO-for-cross-domain-ASP-NET-applic