I've thought about a lot of details of implementing a system with redundant storage, where each provider is given data that is encrypted with a different key to ensure redundancy. So then you would have a "watchtower" system that ensures that each provider - via Merkel proofs - demonstrates that they have your data. If any provider goes down, your watchtower stops paying that provider and then copies (with a new key) your data to another provider

- Use something like git or hashtree ( @Sirius ) to represent the data and allow incremental updates of the Merkel tree

- hierarchical key derivation, so that you can share read-only keys for specific subfolders with other people

- a second layer of encryption, so that your watchtower doesn't see the real clear data; allowing you the freedom to run your watchtower on always-online hardware that you don't fully trust


One of the things I discussed in detail (but we each had different use cases and goals in mind) recently at @Sovereign Engineering @Tom