Idea: The ultimate CD/DVD auditing tool

Major Variola (ret) mv at
Sat Jul 5 22:48:42 PDT 2003

At 04:13 AM 7/6/03 +0200, Thomas Shaddack wrote:
>Pondering. Vast majority of the CD/DVD "protection" methods is based on

>various deviations from the standards, or more accurately, how such
>deviations are (or aren't) handled by the drive firmware.
>However, we can sidestep the firmware.
>The drive contains the moving part with the head assembly. There is an
>important output signal there: the raw analog signal bounced from the
>disk and amplified.
>We can tap it and connect it to a highspeed digital oscilloscope card.

This is a valid idea.  You do have to get in there with delicate probes
to read the amplified analog signal, its not available past the drive.

The people who already do this are called test engineers for CD drive
Or the data-recovery techs for the NSA et al.

I doubt that hardcore pirates bother, they may as well just do a single
high quality
ADC.   That, as has been mentioned here before, is always the fatal
flaw, even
if you put the DAC in your DRM chip (and solve the resulting noise

"Yes, we know they have logic analyzers in Hong Kong" --a Sony engineer
confronted with weaknesses in the design of a DRM box

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