On Fri, 2005-06-24 at 18:13 +0200, Fabrice Rossi wrote: > Pat Farrell a écrit : > > Of course both DVD-A and SACD were supposed to include DRM > > and prevent copying, but as usual, that didn't happen. > > Really?
yes. it really doesn't protect the data. > The high definition content of SACD is protected at the physical level > and it seems nobody as cracked it yet Not clear that anybody cares to. There are very few SACD only recordings, and only a tiny percentage of them would be of interest. You show a clear way to achieve this later in your note. There is not much of a conceptual challenge to cracking any cryptography used by any of the schemes. Good cryptography is about key management. To have a real DRM for hardware players, each player would have to have unique keys. This is against everything that mass market manufacturers want. Doing real cryptography is a lot easier on networked computers, especially with things like the CPU-identification number that Intel put in the Pentium-III. It is impossible to "copy protect" digital media. It is possible to prevent usage of the copied data when you use real cryptography. But this is gettting way off topic for Slim Audiophiles. Contact me off list, or check out the serious cryptography lists for more. > The DRM of DVD-A is similar to the one of DVD (the famous CSS), but it > has not been cracked (see http://en.wikipedia.org/wiki/DVD-Audio). Again, mostly because there is no reason to work that hard. CSS was trivial to break. > The funny thing about those DRM systems is that you can digitize back > the analog output of your player with sufficient quality to produce the > low bitrate MP3 everybody is downloading from P2P network. So they > basically bother people who are ready to buy the things... With a two hundred dollar audio card, you can play the multi-track high res audio out, and re-digitize it at 24/96kHz. Less money for stereo. While it may not be technically bit perfect, who is going to be able to tell one bit mis-quantitized? I maintain that lots of cheap "pro audio" cards can do the job well enough to recover the 100dB signal to noise ratio that the fundamental recording gear has. And with 20hZ to 50kHz bandwidth. It is perfect enough that you can return to arguing about which $500 interconnect cable is better. -- Pat Farrell PRC recording studio http://www.pfarrell.com/PRC _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
