From the Collatz admin:
So what needs to happen is that the WUs need to be encrypted as well as the checkpoint files along with anti-tampering checks to make sure that the checkpoint file belongs to the WU being crunched and hasn't been edited since it was last updated by the app. That means creating new applications and all the server daemons that create, validate, grant credit, etc.
It also means going back through hundreds of gigabytes of result data to try and figure out when the impossibly fast machines first started sending results like that back and regenerating all those work units.