SpiderOak Woes

[rob-IdUdaS/NwSyQrzRDRVclEQ at public.gmane.org (Rob Hasselbaum)]

On Wed, Apr 13, 2011 at 2:13 PM, Gordon Marx <gcmarx-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org> wrote:

> If I upload encrypted data, and I do not give out the encryption key,
> then no "master encryption key" is going to let anyone into that data.
> If there is some way to break AES-256 or RSA, that's a separate issue.
>
>
Is this efficient in practice? For example, if I create an encrypted volume
in TrueCrypt, it shows up on the host file system as just a big file. Is
CrashPlan (or any other backup provider) smart enough to only transfer the
changed bits on each sync? Or is it going to move the whole file every time
some part of it changes?