I've been doing this with a small volume (1 MiB), but it always kept me wondering how much traffic a minor change in an encrypted volume causes - even a single bit flip should drastically change the container if the encryption is good. I wouldn't want to upload for an hour each time I see a typo in my files.
> The ciphertext block size used by TrueCrypt is 16 bytes (i.e., 128 bits).
Meaning one bitflip should only sync 16 bytes since dropbox only transmits deltas. Of course this now depends on dropbox' delta sync implementation.
From a quick google search [1]:
> For what it's worth, Dropbox claims to create hashes on every 4MB of each file. That way, if you change a contiguous 2MB of a 100MB file, it will likely only need to upload 4MB (or 8MB if you cross into a second 4MB block) to re-sync the file.
So worst case if a bitflip happens to change a truecrypt block that doesn't align with dropbox' chunks you're looking at around 8MiB. That's still quite an amout for a bitflip but i think it's feasible with todays connection speeds.
