How to Decrypt DVD's or Blu-Ray Discs?

[johner23]

Which kind of technical knowledge are necessary to know how to create a program by yourself that can decrypt dvd's and blu-ray discs?

Its so hard to do it? So deep or specifical knowledge are needed?

For example, if I buy one disc dvd for myself and I want to study all its protection's mechanism, how to start? To see how that protection works and how to defeat them? Which tools are needed to do it?

I mean, for example, how AnyDVD or DVDFab 's team staff "study" all the dvd's and blu-rays released on the market, analyse and discover all the ways to decrypt them?

Thanks.

[paradoxical]

For DVD, you need DeCSS and how to break all the secondary copy-protection schemes. Some of the latter are easier than others. For BluRay you need to be able to decrypt AACS and you need to constantly update your decryption software to match the latest changes in BD+.

How exactly either of those teams do their work to break these copy-protection schemes is probably a pretty closely held secret. For one thing, they don't want to tip the media companies off on how they are doing it nor are they probably wanting others to be able to copy their methods. Being able to reverse engineer what a licensed DVD and/or BD player does would certainly be a good start. For BluRay your likely to need your own implementation of a BD+ virtual machine. A good thread to start on that would be here (http://forum.doom9.org/showthread.php?t=140571) or check out libbluray.

[Ghitulescu]

Which kind of technical knowledge are necessary to know how to create a program by yourself that can decrypt dvd's and blu-ray discs?

Its so hard to do it? So deep or specifical knowledge are needed?

You need first to know programming :)
Then you need to know how a DVD/BD internally works. For this you need to qualify for a very expensive "Specification" or to try to pick up the bits from fora like this one. It also requires a lot of testing (buying the real DVD/BD, maybe more than once, since various pressings may have different protections, and testing them one by one)
Finally, while the writing "per se" is not illegal, the use of the final program is (under a lot of jurisdictions, number increasing ;) ).

[setarip_old]

Its so hard to do it?Perhaps the most difficult thing is keeping up with the new and/or modified protection concepts that are constantly being created ;>}