This paper is interesting, but I think it's important to note that this is covering one particular problem that is somewhat different than what most users of cl

This paper is interesting, but I think it's important to note that this is covering one particular problem that is somewhat different than what most users of cloud backups are looking for: client side, encrypted de-duplication of files ACROSS CLIENTS. That is, that you want to de-duplicate A,B's files without being able to reveal to A, B, or a honest-but-curious hosting provider that there is a duplication of content. Most backup schemes only care about de-duplication within the context of a single user; that is, A's files are de-duplicated between backups only against A's files, and even if B uploads an identical file, it is stored twice on the provider's servers.