I would like to understand any applicable methods for testing the user experience when entering sensitive financial information, specifically as part of usability testing with interactive prototypes. We're limited to remote unmoderated at the moment with the COVID situation.
The only approach I can really see is providing fake credentials to the user as part of the test setup. But I don't believe this approach replicates the real world friction/trust barriers which must be overcome. Another approach would maybe be to design a trust focussed test separate from the specific feature I'm testing, but I worry this could easily become disjoined from the core testing purpose of this feature and expand into an overall "do you trust this test platform" as well as "do you trust this app" enough to enter sensitive details which seems to ruin the purity and overall method.
In this example it's not possible for me to use real world credentials and remove them afterwards as the onward flow from credential entry cannot be mocked out in an effective way.
I found one previous question on SE which looks similar usability testing with sensitive and private information but it's back in 2015 and the only answer describes what I've already considered.
Has anyone seen/used any novel/effective ways of testing this kind of workflow?