[Discuss] encryption and rsync

[richard.pieri at gmail.com (Richard Pieri)]

On 7/16/2012 1:59 AM, Tom Metro wrote:
> But I'm assuming that EncFS isn't doing anything to assist the syncing
> of partial files, so your minimum transfer is a full file.

Like I said, I've been experimenting, and I've found how to make this 
work better with rsync/unison.  Hooray for reading the manual :).

EncFS has an option called per-file initialization vectors (IVs) which 
is enabled by default.  This option generates a 64-bit random IV for 
each file written.  This ensures that encrypted blocks are never 
identical.  If you turn per-file IVs off then block encryption becomes 
deterministic, which is a fancy way of saying same cleartext in, same 
ciphertext out.

rsyncrypto uses the same kind of not-random IVs with similar results.

-- 
Rich P.