I use the dynamic proxy to create proxies for com+ exposed web services. I want to use wsHttpBinding with transport security mode with SSL using client certificate for authentication. To address this scenario you have to modify the proxy adding a Credential property on DynamicProxy type. public ClientCredentials Credentials { get { return (ClientCredentials)base.GetProperty("ClientCredentials"); } } From your code you can use this to set the certificate. In my case the client is an asp.net app so the certificate in the...