We need to allow access for 3 members of our HR staff to sensitive payroll information that is stored in files (not in a database). I want to ensure that our administrators cannot access the data. It seems counter-instuitive to assume that this can be done with folder or file rights, so I think I am looking for an encryption method like EFS, but that will allow for multiple user access.
This information may reside on an on-premise server, or it may reside in a Sharepoint Online document library.
What would you suggest we look at?
Thanks in advance,