Re:Dropbox (YC S07): Simple Tasks for Extra Space (768MB total)
by jodrellblank on Tuesday November 23, 2010 @10:44AM
(#1934012)
One of the properties of a good hash algorithm is that a small change in the input makes a big change in the output, and one of the properties of a good encryption algorithm is that the output looks random.
I don't know how the two are supposed to combine, but the prediction is that for a truecrypt disk image, any change in the contents produces a very different disk image all over - so transferring "the delta" is still a much larger amount than you'd expect.
Although, if this were the case it would also have to rewrite the disk image a lot and that might be quite bad for just local use.
Re:Dropbox (YC S07): Simple Tasks for Extra Space (768MB total)
by Dylan16807 on Tuesday November 23, 2010 @06:08PM
(#1935766)
The encryption is block based. Change a bit and you're completely scramble the block, but no more.
As far as I can tell from my own usage, the only portion that is uploaded is the changed portion. I have a 1GB container currently synced and when I change files in that container, I can assure you that it doesn't upload 1GB of information. It appears to only transfer the delta.