I think this is the client I want to use for replicating my desktop like Max Hodak describes[1]. It sure has enough options for target storage.
It boasts client-side encryption, but the author says that "In terms of speed, Syncany only transfers the changes of files, so if you change only a couple of bytes of a 100 MB file, only those bytes which have changed will be transferred (+ some more)[2]."
Sounds like it uses homomorphic encryption[3]. I don't have the skills to read the code and know whether it's well done. Can anyone comment?
It is very unlikely to be using homomorphic encryption; it's only 2011, after all.
There are any number of ways to store an encrypted file such that you can transfer deltas to it instead of entire new versions. They support different kinds of deltas. Some of them are secure.
Oh, thanks. I thought updating encrypted files required transferring the whole file, but I can see now how one could encrypt files in chunks and only transfer the updated chunks.
It boasts client-side encryption, but the author says that "In terms of speed, Syncany only transfers the changes of files, so if you change only a couple of bytes of a 100 MB file, only those bytes which have changed will be transferred (+ some more)[2]."
Sounds like it uses homomorphic encryption[3]. I don't have the skills to read the code and know whether it's well done. Can anyone comment?
[1] https://www.maxhodak.com/notes/2011/05/30/dropbox.html
[2] http://www.webupd8.org/2011/05/syncany-great-dropbox-alterna...
[3] http://en.wikipedia.org/wiki/Homomorphic_encryption