From: James Rogers (jamesr@best.com)
Date: Thu Jul 13 2000 - 09:28:59 MDT
On Thu, 13 Jul 2000, you wrote:
> Fra: Michael S. Lorrey
>
> >Actually, no. If the file is encrypted such that each successive play requires a
> >new key to decrypt, which must be downloaded from the recording company's
> >keyserver on a pay per play basis (i.e. no key can be used twice on the
> >same downloaded file), then you have a very secure file format.
>
> Well I will then write a small app that reads the values sent to /dev/audio
> and will have a perfect copy from there ... If it is output digital anywhere
> without the key, it can be copied.
Which is the crux of the problem. If you control the hardware, you can
get the unencrypted data. Any protocol that uses software encryption is
necessarily hackable from the start. The only reasonably protected
options wouldn't fly in the market because they would essentially take
over your systems at the hardware level -- something that would
effectively be a "security through obscurity" solution if practical.
> I can even wire up another computer and just record it with that. very small
> loss in quality.
With current top end 24-bit project cards and good audio drivers, you
could easily get a dithered audio signal that was essentially as good as
the Red Book source recording. With a loopback through your converters you
could get a super-clean Red Book digital recording that was essentially
perfect.
Also, and more importantly, purely digital audio interfaces (SPDIF,
AES/EBU, ADAT, TDIF, etc) are valid audio outputs on every operating
system that I've ever used. It would trivial to tap a lossless digital
signal off one of these interfaces.
-James Rogers
jamesr@best.com
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