This is a core promise of the SWITCH edu-ID: An individual should be able to use one single digital identity to authenticate, while at the same time being able to choose the appropriate organisational role – or, using a more technical and precise term, the appropriate affiliation – in which to enter a service.

For members of organisations which have already adopted the SWITCH edu-ID, this concept has now arrived in the real SWITCH edu-ID world. The module called “affiliation chooser” is now executed right after authentication. It lets the user choose the appropriate affiliation, before consenting to attribute release and service access.

The affiliation chooser is intended as an intelligent replacement for the well-known discovery service (WAYF). The good thing about the affiliation chooser is that it knows when to show a choice at all. Unlike the WAYF, it only bothers the end user with its question when it really needs to. If e.g. the end user has only one affiliation, then there’s no real choice. Most edu-ID users have just one single affiliation to an organisation, if at all, which is then the one to present to the service. On the other hand, if the service allows only one affiliation, then again, this is the one to check against, even in the rare case when the user has more of them. In a more complex scenario, the affiliation chooser would actually do some set operation. The intersection of all affiliations the service is intended for, with all affiliations that an end user has, may actually contain zero, one, or more items:

• If no affiliation remains, then the user, although correctly authenticated, cannot be admitted to the service, as none of his affiliations would fit. This check is now being done by the edu-ID IdP, before the user is sent to the service.
• If there remains exactly one out of this intersection, then it’s the one to choose. No need to bother the end user with a choice if there’s just one item to choose from.
• If multiple affiliations remain, then this is where the end user actually sees something. A dialog box similar to the one in figure 1 is shown, and the end user has to choose the affiliation – given by a certain set of attributes – to present to the service. Based on these attributes, the service can then assign the appropriate privileges and access rights.

Figure 1: The Affiliation Chooser

What’s in for the end user?

Once the organizations the users are affiliated with adopt the SWITCH edu-ID, the end users will see much fewer possible choices in the affiliation chooser than they currently see in the discovery service. At the point of writing this article, only SWITCH has adopted the SWITCH edu-ID, therefore this currently only applies to SWITCH staff members.

What’s in for the services?

When registering with the federation, services declare their “intended audience”, and thus give an upfront indication about which organizations users must have an affiliation with, in order to be allowed on the service. This indication is picked up by the affiliation chooser which then puts it into an intelligible form and thus helps in pre-filtering the users arriving at the service.

Certain services allow for “private identities”, i.e. without any affiliation to an organisation. In that case, the affiliation chooser flags this possibility separately. Figure 1 shows this as “Private Person” option.

Future services might be able to cope with more than just one affiliation at a time, as the “extended attribute model” in the Swiss edu-ID Architecture suggests. For such services, the affiliation chooser won’t be needed, as no affiliation would have to be chosen at that point.