I'll have to try using plain git annex from the commandline to try to understand what is going wrong (I already used it to clean some repositories that the assistant was refusing to delete)
PS: I tried it with 2 machines in the same LAN (both linux... though one of the 2 distros had a slightly older version of the git-annex package)
The default MAC algorithm to be applied on the filenames is HMACSHA1. A stronger one, for instance HMACSHA512, one can be chosen upon creation of the special remote with the option mac=HMACSHA512. The available MAC algorithms are HMACSHA1, HMACSHA224, HMACSHA256, HMACSHA384, and HMACSHA512.
In any case, while I want security in these systems to avoid mass survey style attacks, I assume anything I put over the wire to be compromised at least potentially. I keep the kind of files that need that level of encryption on encrypted flash drives.
That doesn't follow - you can solve the problem without containers, e.g. by encrypting or hashing the filenames.
Containers protect the file sizes, but they lose the ability to selectively sync certain files to certain nodes.
Regarding selective sync : you'll have to organize the files logically into containers. I think even Dropbox doesn't let you sync files selectively, you have to have content separated into folders.
I'm not saying that one is better than other, just giving an example of where de-duping at block level is needed as @lugg asked.
Sure; I was just talking about the file names. You can avoid the hierarchy part by transmitting it separately from the files in a secure way, though.
Regarding selective sync : you'll have to organize the files logically into containers. I think even Dropbox doesn't let you sync files selectively, you have to have content separated into folders.
git-annex does. You can implement rules to decide what files should be synced, which should be dropped locally, etc.
For example, an MP3 player running it might have a rule such as
filename(*.mp3) or filename(*.ogg)
For now I run seafile inside a private network behind a vpn. But I'd rather find an alternative with a better security story. Something from a team that can justify their cryptographic constructs in detail.