That's the value proposition of something like Siacoin or Filecoin. If Dropbox did that, you wouldn't be able to reset your password (since they do not store y

That's the value proposition of something like Siacoin or Filecoin. If Dropbox did that, you wouldn't be able to reset your password (since they do not store your password, just a salted hash, I hope). Dropbox does plenty of interesting things with its users' files to optimize storage. I know they dedupe files, probably using a file hash. Perhaps they optimize even further.