I have developed a WPF application which communicates with a set of self hosted WCF services which are under same domain and I use the following setup in the config files. <security mode="Transport"> <transport clientCredentialType="Windows" protectionLevel="EncryptAndSign" /> <message clientCredentialType="Windows" /> </security> I hosted the services on a server in different domain .I can achieve the communication by setting the security mode to "None" which is not ideal. Is there any other setting i can user for cross domain communication or i have to do with some trusted certificates ? I would be glad if some one can guide me because all the searches on google directed me to silverlight applications +Crossdomain.xml+WCF but i have't seen any combination of WPF on crossdomain environment.