How well does Deepstream work with offline periods, e.g. stuff being created/modified on a disconnected mobile device that later connects and needs to sync? Is

How well does Deepstream work with offline periods, e.g. stuff being created/modified on a disconnected mobile device that later connects and needs to sync? Is it possible to make it work in a way that the server only sees encrypted data? I can see it working in a clunky kind of way if each client had two versions of each document, a clear one that is operated on, and one encrypted (possibly a record at a time or something) that is synced.