If you are associated with a university or other academic organization using kerberos as authentication mechanism, you can select SSVL as upstreams provider from StockholmOpen.Net and login via kerberos using your regular <username>@<REALM> as user and your regular kerberos password as password so that your home organization can authenticate you.

Just to be sure, send an email to noc@ssvl.kth.se before trying this so that we can check that your university is among the approved organizations in our database.