On Wed, Feb 22, 2006 at 03:34:44PM -0800, Kevin Till wrote:
> >- What is the point to uuencode and encrypt (with gpg) random data to
> >  generate the key?  Since the passphrase is stored on the same host,
> >  protecting the key with the passprase is not of much use (IMHO).
> 
> It illustrates the method of using multi-key which a strong point of 
> aespipe.

OK, I see.  "multi-key" was the magic word that (after some googling)
made me understand what's going on here.  AFAICS, multi-keys can prevent
watermark-attacks?  Are there more advantages to them?

> And it's a symmetric encryption and to facilitate automatic 
> backup, the passphrase has to be stored somewhere.

This is (one) of the reasons why I'd prefer a pubkey method: You don't
have the passphrase lying around on a networked box.

> >- Why using aespipe at all?  Is there any reason not to use gpg?
> >  AFAICS, aespipe introduces only an additinal layer of complexity.
>  Amanda users have used aespipe in the past, so it's there.

Hmmm, AFAIK is aespipe part of loop-aes and loop-aes is deprecated
because the kernel developers want to switch to devmapper.  Please
correct me and clarify if I'm wrong.

>  I believe aespipe gives better performance since gpg is doing more 
>  than just encryption.

AFAIK, gpg does compression in addition to encryption.  But then you need
to compare gzip+aespipe against gpg.  Or did you mean something different?

> >- Since the server says whether/which encryption is to be used, the
> >  server can request unencrypted backups from the client.  This
> >  implies that the server has to be trusted.
> 
>   Use "auth ssh/krb4/krb5" to enable transport encryption.

I am not about transport encryption here.  I am about not trusting the
amanda server.

Thanks for the explanations, Kevin!