In an embodiment a method is performed by a network access device (NAD). The NAD transfers a first HTTPS request from a client computer (UE) to an identity provider computer (IdP). The NAD transfers, from the IdP, a preceding redirected URL in response to the first HTTPS request, to the UE and configured to cause the UE to redirect to said preceding redirected URL. Over a secure network link, the NAD receives a particular request specifying said preceding redirected URL, from the UE. Responsive to receiving the particular request, the NAD generates a response, comprising a subsequent redirected URL and a session identifier, and configured to cause the UE to redirect to the IdP over an HTTPS connection. The NAD transfers said subsequent redirected URL over the secure network link to the UE. The NAD transfers a second HTTPS request, comprising the session identifier, from the UE to the IdP.