This is interesting. I designed a similar system a few years ago, although the company ran out of runway. We made many of the same design choices. A few smal

This is interesting. I designed a similar system a few years ago, although the company ran out of runway. We made many of the same design choices. A few small observations: 1) GCM encryption is limited to 64GB under the same key/IV. Files bigger than that may need splitting up. 2) GCM is broken if you reuse an IV with the same key. So be very careful here. 3) I don't see anything about how synchronisation works. When multiple clients can read or update a central store, clients really need to know which is the latest. We used vector clocks for this to get event ordering. Some care is needed to preserve privacy and integrity and performance when adding in additional metadata.