[Dvdrtools-users] Re: crypt ISO image -- can't encrypt images any more than you can compress

[Alessio Sangalli]

Bryan J. Smith wrote:

> First off, an .iso is an image of a filesystem, ISO9660 or UDF 
> specifically.
>
> Secondly, if you crypt/compress the .iso, you can't burn it with 
> cdrecord AFAIK.
>  If I'm wrong, please correct me.

This would be an interesting test.


> You'd be better off doing encryption on a per-file basis, then 
> mastering the
> image from that.

I don't only want the files to be crypted, but even the content 
shouldn't be guessed. A complete protection over which kind of data, 
files, filenames are in the DVD.

A 'per-file' encryption is not so difficult to realize just before the 
actual image creation and I know how to do it. However I would like to 
protect the 'whole' dvd globally, I don't know if I can correctly 
express my need.

> So you're not talking about burning it to media, but just leaving it as a
> "single file" on your hard drive?  If so, then you _can_ do such using the
> loopback device.

I explain better the original idea:

1) I prepare my data
2) I generate an ISO image file with mkisofs
3) I encrypt it
4) I take the encrypted ISO image and I burn it to a dvd-r with 
dvdrecord or cdrecord-hack
5) I delete the data, the ISO, and the encrypted ISO from the hard disk
6) I put my dvd-r on the shelf for months

when I need the data...

7) I read the dvd with 'dd' on hard disk
8) I decrypt it
9) I mount the decrypted ISO image file as loopback OR I burn a DVD-R 
with it

I think the only problem would be in step 4), probably the ISO image is 
not valid anymore and can't be burned on DVD.

Stupid question: can I generate a local copy of a dvd (step 1) with dd? 
With data cd-roms I gave a: "dd if=/dev/hdc of=file.iso bs=2k" I don't 
know if this is ok with data DVD-roms, video DVD, whatever...


> >I think I understand your point. I will try the 'iso into an iso'
> >system...
>
>
> .iso into .iso???


on another mail I was told to simply generate the ISO, encrypt it, and 
then generate another ISO containing the encrypted ISO. This will 
obviously work....



bye and thank you
as