Copyright: CSS/CPPM?

[X-treme]

I tried running a search, but could not find really what this means.

I always see CSS when I decrypt, but what's the purpose of CPPM? I heard it's a 'stronger' method for decryptors?

Is it still possible to decrypt both of these with dvd-decryptor without any problems?

Anything I should know?
Thanks

[indolikaa]

Content Protection for Pre-Recorded Media.
http://www.disctronics.co.uk/technology/dvdaudio/dvdaud_copyprot.htm


It's used for DVD-Audio. I've not heard of a decrypt yet for it.

[X-treme]

So If I were to copy a movie with these setting it would alter the original dvd?

[indolikaa]

No.

The purpose of the decrypter is to allow you to unlock the DVD. Other than removing the protection scheme, it will have no effect on the movie.

CPPM is not an issue for movie discs. CSS is.

[X-treme]

Thank-you for clarrifying this, but I'm still confused.

CSS does what? Does it somehow alter the original movie?

My main concern is, if the movie I am ripping has both protections on it, what are things I should be aware of?

After reading your link about CPPM, it talks about watermarks on the dvd and how they can be altered from copying.. etc.. no?

[X-treme]

Bump.

Could anyone help me out?

As stated above, my main concern is, if the movie I am ripping has both protections on it what are things I should be aware of with css/cppm? Does dvd-decryptor have any problems decrypting?

Thanks for any info.

[indolikaa]

What movie are you trying to rip?

[Cornucopia]

You can get more info at DVD DeMystified, but a short synopsis:

For Pre-recorded stuff (aka factory stamped / pressed media)

1. DVD-ROM zone has no specific form of copy protection, but you can use any of the usual methods to encrypt, e.g. PGP, Blowfish, etc.

2. DVD-Video zone has Analog protection in the form of Macrovision, and Digital protection in the form of CSS. As you know, both of these can be circumvented.

3. DVD-Audio zone has no form of Analog protection, but does have Digital protection in the form of CPPM. As of this date, there is no known way of circumventing this type of protection.

There are additional protections which can be applied to recordable/burnable media. This is known as, not surprisingly, CPRM.

AFAIK, that's the state of things.

If you are seeing both CPPM and CSS on a disc, it must be a "Universal" disc with both DVD-Video and DVD-Audio material. You should still be able to decrypt the DVD-Video material, but you won't have as much luck with the DVD-Audio. 'Course, you can always send it out via the soundcard, and recap.

Scott

[X-treme]

There is no specific movie that I would like to rip, but the majority of movies I have seen have both copyrights (css/cppm) on them.

I just want to make sure that if I rip movies with these encryption that i will no alter the original movie in any way?

[indolikaa]

I have NEVER seen a movie with CPPM. The CPPM standard was authorized for DVD-Audio disks. The Media Key Block (MKB) works in such a way that current DVD-Video players would NOT be able to play such a disc.

I took my information straight from a industrial mastering facility that mass-produces pressed DVDs. The same DVDs you buy with a movie already on them. CPPM and Watermarking are techniques that will are being used to keep us from copying DVD-Audio.

Use DVDDecrypter to remove the encryption and you will be left with an identical copy of the movie.

Now what your discs likely have is both CSS and Macrovision. One is used to prevent digital ripping, the other is used to prevent analog copying. If you rip, Macrovision is not an issue.

[X-treme]

Thanks for the info once again.

After checking three of my movies (ex. Out of time, and Bad boys II S.E) they both show up as Copyright protection system type: CSS/CPPM.

Each time you posted I had a mixed thought because it sounded as if CSS is not 'decryptable', but as your posts continued, you state one can decrypt if css/cppm are on the dvd.

[indolikaa]

Now I could be wrong on this, and believe me it wouldn't be the first time...


This sounds like a poor choice of wording by the author of the software in question. Rather than specifically identify the encryption, they are just grouping CSS and CPPM together as if they were the same system. They are not! They are two completely different methods of encrypting digital data.

This is a quote straight from Jim Taylor's DVD FAQ at dvddemystified.com...

4) Content Protection for Prerecorded Media (CPPM)
CPPM is used only for DVD-Audio. It was developed as an improvement on CSS. Keys are stored in the lead-in area, but unlike CSS no title keys are placed in the sector headers. Each volume has a 56-bit album identifier, similar to a CSS disc key, stored in the control area. Each disc contains a media key block, stored in a file in the clear on the disc. The media key block data is logically ordered in rows and columns that are used during the authentication process to generate a decryption key from a specific set of player keys (device keys). As with CSS, the media key block can be updated to revoke the use of compromised player keys. If the device key is revoked, the media key block processing step will result in an invalid key value. The authentication mechanism is the same as for CSS, so no changes are required to existing drives. A disc may contain both CSS and CPPM content if it is a hybrid DVD-Video/DVD-Audio disc.

[X-treme]

I just finished backing-up an old movie of mine that has both css/cppm copyrights, and I dont believe I encountered any problems?

How would I know? The original movie doesn't seem to be changed at all? ( I don't think it would be, no?)

[indolikaa]

If the disc plays, you already have your answer.

[X-treme]

I've heard stories that their movie had css/cppm and it froze and displayed signs of errors because of the decryption.

Why do individuals state that they cannot decrypt/copy a movie with these protections then? I don't understand?

[indolikaa]

You're not understanding something, here.

* CPPM does not exist on DVD-Video discs. It is not a valid encrypton scheme approved by the DVD Forum for DVD-Video discs. It is not used on DVD-Video discs and is therefore not an issue. CPPM only protects material that meets the specifications for DVD-Audio for Read-Only Discs, Part 4 Version 1.2.

That movie disc you're holding in your hand is not covered under that specification.

* A DVD player cannot play any disc that has CPPM unless the machine also supports the DVD-Audio specification. There is an authentication process that requires hardware to unlock CPPM. If you don't see the 'DVD-Audio' logo on your DVD player, it won't play any disc with CPPM protection.

* CPPM has not been hacked! If you truly were ripping a disc with CPPM protection it would not play on your DVD player.

You ARE NOT removing CPPM from any of your discs. You are only removing CSS.


As for those stories you've heard? Shit media, bad burning methods, trying to burn at 8X on a 1X discs, burning while playing Quake, I could list a lot of reasons why they would run into problems.