Use a autenticação de certificado rdp.
@Scott Chamberlain descreveu este link :
Yes but you will need to install and configure your Remote Desktop Session host to use a Remote Desktop Gateway to do it.
Once you are using a Remote Desktop Gateway you can set up Remote Desktop Connection Authorization Policies (RD CAPs) and Desktop Resource Authorization Policies (RD RAPs) in those you can set things up like requiring that a connecting machine has a client certificate (per machine or per user).