It is important that neither group be impersonated. - How can I verify the identity of both groups? - How can I verify that the citizen lives in the zipcode they provided?
Any tools, libraries, methods, services are welcome!
Thank you in advance.
For government employees, that might have to be done by hand, by verifying through public records.
For people... maybe require a small temporary credit card change with a billing address matching their inputted zip code?