What encryption algorithm and key length is used on the following binding?
NetTcpBinding binding = new NetTcpBinding();
binding.Security.Mode = SecurityMode.Transport;
binding.Security.Transport.ClientCredentialType = TcpClientCredentialType.Windows;
From MSDN:
So it’s going to depend on your operating system which version of TLS is used. For Server 2008 R2, TLS 1.2 is used.
Hope that helps.