This is a very interesting development. Encryption generally would solve a lot of problems around data sovereignty. So, encrypting the data, keeping the key and moving the data to the public cloud could basically address a lot of the risks. Today, it comes with a high price as the data which resides encrypted in the Cloud cannot be index (therefore is not searchable) nor can any operation be conducted.
The solution is homomorphic encryption, where a lot of research is done but it is still too slow. People at Microsoft Research now took a new angle on it: They took, what is already here and looked at the scenarios, which are already possible today.
The following article gives an interesting overview, what would be possible based on todayâ€™s research: A Cloud that Can’t Leak