To allow authenticated access to your University of Otago website for people from other institutions, you would need to become a service provider, and this option is not currently being supported by ITS.
However if you are setting up a University of Otago website that you want to be able to allow authenticated access to, you should ensure that the website software is Shibboleth-compatible. This is indicated by the Shibboleth logo:
Further information
Tuakiri/Tuakiri NZ Access Identity Federation
Using the Tuakiri Federation system