I still think there might be something here. You can allow certain aggregations (like “sum of the tax column”), but they have to be explicitly permitted; otherw

I still think there might be something here. You can allow certain aggregations (like “sum of the tax column”), but they have to be explicitly permitted; otherwise shuffle and hash everything enough times to make a single lookup sort of cheap, while a scan very expensive (plus distribute over enough physical servers and make the network between them low bandwidth to thwart lower level attacks). With enough regulatory or legal pressure on companies to lock down their data, paying this premium might start to look attractive; one could even found a startup peddling the World’s Slowest Database™! Edit: what I was thinking originally was that in the world of paper-only archives, these massive leaks were all but impossible, yet business could still be done. It should be possible to combine this slowness with the convenience of computers.