# How does the new CD copy protection work? **URL:** \ **Category:** Factual Questions\ **Created:** [September 27, 2001, 6:31pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160 "2001-09-27T18:31:39Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [September 27, 2001, 6:31pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/1 "2001-09-27T18:31:39Z")
Just curious. Per this linked MSNBC article it sounds powerful but there are no technical details as to how the anti-copy mechanism works and I’m not sure how a CD would, or could know if it was being copied once, twice or a million times. Anyone have more complete info as to how this technology is being implemented? > **[MSNBC News - Breaking News and News Today | Latest News](https://www.msnbc.com/)** > > MSNBC breaking news and the latest news for today. Get daily news from local news reporters and world news updates with live audio & video from our team. ---
**Author:** ![Syzygy](https://avatars.discourse-cdn.com/v4/letter/s/bc79bd/32.png) [@Syzygy](https://boards.straightdope.com/u/Syzygy)\ **Post date:** [September 27, 2001, 6:37pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/2 "2001-09-27T18:37:22Z")
The article I read said that the scheme introduces random noise at regular intervals. The noise is of such short duration that the error-correcting software built into audio CD players could handle it with out you hearing it. A CD-ROM drive, however, would read it cold, adding the imperfections into any .wma or .mp3 file you create from the CD, making them worthless. ---
**Author:** ![micco](https://avatars.discourse-cdn.com/v4/letter/m/5f8ce5/32.png) [@micco](https://boards.straightdope.com/u/micco)\ **Post date:** [September 27, 2001, 6:44pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/3 "2001-09-27T18:44:05Z")
**Syzygy** ’s explanation is backed up by this article: [http://www.newscientist.com/news/news.jsp?id=ns9999998](http://www.newscientist.com/news/news.jsp?id=ns9999998) But it also says “Macrovision is reluctant to discuss how SafeAudio works.” ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [September 27, 2001, 7:23pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/4 "2001-09-27T19:23:55Z")
> [@](#): > > _from the OP’s link_ > When this happens, a consumer CD player bridges the gaps. It looks at the music on either side of the gap and interpolates a replacement section. A computer does the same when playing CDs for listening. This isn’t consistent with what I’ve heard about the CDs… everything I’ve read says that they won’t play at all in a CD-ROM drive, and in fact that’s why [this woman](http://dailynews.yahoo.com/h/ap/20010919/tc/cd_suit_1.html) is suing over them. > [@](#): > > _from my link_ > SunnComm’s technology allows the CD to be played in conventional devices such as stereo systems and portable CD players. Computer CD drives, however, will not play it. > > Instead, once the CD is placed in a computer CD tray, the user is directed to a Web site where the song tracks can be downloaded in a protected digital format. Those downloaded files can’t be burned to CD or shared with file-sharing programs. OTOH, this may be an entirely different system from Universal’s. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [September 27, 2001, 7:29pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/5 "2001-09-27T19:29:02Z")
That explanation seems quite poor and doesn’t make much sense. If the boomboox can do it, so can the computer. I cannot see why not. Other protection schemes rely on requiring the reader (drive) to participate in the scheme. This would work but it means you could not read the CD with old equipment. We are talking digital extraction because you can always just copy from the analog signal. ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [September 27, 2001, 7:34pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/6 "2001-09-27T19:34:26Z")
Also, from what I understand of how CDs work, the same error correction is used whether reading the CD to play it or to digitally extract it. Audio sectors don’t have error correction checksums like data sectors do (which saves a lot of space, letting you fit 74 minutes of audio - 740MB - on a disc that only holds 650MB of data). ---
**Author:** ![KeithB](https://avatars.discourse-cdn.com/v4/letter/k/48db29/32.png) [@KeithB](https://boards.straightdope.com/u/KeithB)\ **Post date:** [September 27, 2001, 8:19pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/7 "2001-09-27T20:19:59Z")
Hmm, I wonder what audio CDR’s will do, after all I am _paying royalties_ to be able to copy discs. ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [September 28, 2001, 12:45am UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/8 "2001-09-28T00:45:07Z")
> [@](#): > > Hmm, I wonder what audio CDR’s will do, after all I am _paying royalties_ to be able to copy discs Don’t know if you were being sarcastic or not, but so-called ‘audio CDRs’ are absolutely no different physically from any other CDRs. Other than, like you said, costing more for the royalties. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [September 28, 2001, 1:52am UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/9 "2001-09-28T01:52:42Z")
> [@](#): > > \*Originally posted by Mr2001 \* > **…Instead, once the CD is placed in a computer CD tray, the user is directed to a Web site where the song tracks can be downloaded in a protected digital format. Those downloaded files can’t be burned to CD or shared with file-sharing programs…** And I predict this will be cracked within about…3 weeks after the CDs become widely distributed. ---
**Author:** ![dead0man](https://avatars.discourse-cdn.com/v4/letter/d/edb3f5/32.png) [@dead0man](https://boards.straightdope.com/u/dead0man)\ **Post date:** [September 28, 2001, 5:22am UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/10 "2001-09-28T05:22:26Z")
I dont have technical information, but what people have said is pretty much the same way I have heard that its done. At least as far as game CDs go, the company will put “faults” on the CD (irregualar code) that when playing(or installing) the game, the game knows not to pay any attention to those bad spots. But when your burner see’s the bad spots the software assumes a fault on the cd and stops the burn. On the other hand, along the lines of what Anthracite said, there will be a “fix” soon after this is released. There are allready programs you can get (cloneCD is the one I use) that will copy a CD “faults” and all. dead0man ---
**Author:** ![Niobium\_Knight](https://avatars.discourse-cdn.com/v4/letter/n/bc8723/32.png) [@Niobium\_Knight](https://boards.straightdope.com/u/Niobium_Knight)\ **Post date:** [September 28, 2001, 11:48am UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/11 "2001-09-28T11:48:37Z")
i have a feeling the added noise may affect sound quality even on a normal CD player. may be subtle but it will more than likely be a bad thing. ---
**Author:** ![micco](https://avatars.discourse-cdn.com/v4/letter/m/5f8ce5/32.png) [@micco](https://boards.straightdope.com/u/micco)\ **Post date:** [September 28, 2001, 1:23pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/12 "2001-09-28T13:23:47Z")
There’s a story here with a little more info: > **[Technology News](https://www.cnet.com/news/)** > > CNET news editors and reporters provide top technology news, with investigative reporting and in-depth coverage of tech issues and events. It’s a fluffy news piece, so no more technical detail than the other link I posted, but it does have more information on the companies involved as well as a brief discussion of cracks. ---
**Author:** ![slortar](https://avatars.discourse-cdn.com/v4/letter/s/6bbea6/32.png) [@slortar](https://boards.straightdope.com/u/slortar)\ **Post date:** [September 28, 2001, 2:49pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/13 "2001-09-28T14:49:09Z")
Does anybody know of any bands with protected cd’s that don’t suck (e.g. I know Michael Jackson’s new CD will be protected, but…)? I really want to give cracking 'em a shot. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [September 28, 2001, 2:51pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/14 "2001-09-28T14:51:02Z")
Some cd copy programs stop on error but others you can tell them to keep copying. ---
**Author:** ![KeithB](https://avatars.discourse-cdn.com/v4/letter/k/48db29/32.png) [@KeithB](https://boards.straightdope.com/u/KeithB)\ **Post date:** [September 28, 2001, 3:00pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/15 "2001-09-28T15:00:16Z")
> [@](#): > > \*Originally posted by Hail Ants \* > \*\* > > > [@](#): > > > > Hmm, I wonder what audio CDR’s will do, after all I am _paying royalties_ to be able to copy discs > > Don’t know if you were being sarcastic or not, but so-called ‘audio CDRs’ are absolutely no different physically from any other CDRs. Other than, like you said, costing more for the royalties. \*\* I know that, but if I am paying royalties I am legally entitled to make copies. I hope that the Audio CDR’s just copy the disc – warts and all – without trying to decode things. I guess, if they get the errors just right, then the interpolation will be the exact same value as the original data and be inaudible. But, do all CD players have the same interpolation algorithm? There used to be a CD player (Harmon Kardon?) that had an LED to indicate that the ECC was operating and another LED to indicate that interpolation was operating. The idea being that if the ECC signal flashed occasionally, no big deal. If the Interpolation light flashed the CD was hosed. Aren’t these CD’s going to be pretty susceptible to scratches without ECC? ---
**Author:** ![NutWrench](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nutwrench/32/20193_2.png) [@NutWrench](https://boards.straightdope.com/u/NutWrench)\ **Post date:** [September 28, 2001, 3:50pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/16 "2001-09-28T15:50:27Z")
There’s nothing to prevent you from running a connector cord from your CD player into the ‘Line In’ on your computer and recording that way. This ‘protection scheme’ is just going to piss off people who play audio CDs in their CD-ROM drives. ---
**Author:** ![Fenris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fenris/32/498_2.png) [@Fenris](https://boards.straightdope.com/u/Fenris)\ **Post date:** [September 28, 2001, 4:11pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/17 "2001-09-28T16:11:15Z")
> [@](#): > > \*Originally posted by Hail Ants \* > \*\* > > > [@](#): > > > > Hmm, I wonder what audio CDR’s will do, after all I am _paying royalties_ to be able to copy discs > > Don’t know if you were being sarcastic or not, but so-called ‘audio CDRs’ are absolutely no different physically from any other CDRs. Other than, like you said, costing more for the royalties. \*\* Not true. There’s something (and I’ve never gotten a clear answer as to what) different, as my stand-alone Stereo CD burner (like [this](http://www.jvc.com/product.jsp?productId=PRD1600000) one) detects if the CD is an Audio CD and won’t work if it’s not. So, whether it’s a formatting issue, a media issue ,or what, _something’s_ different or the burner wouldn’t be able to detect the difference. Fenris ---
**Author:** ![mblackwell](https://avatars.discourse-cdn.com/v4/letter/m/5fc32e/32.png) [@mblackwell](https://boards.straightdope.com/u/mblackwell)\ **Post date:** [September 28, 2001, 4:29pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/18 "2001-09-28T16:29:30Z")
The stand alone audio CD burners do that to seperate you from your money. There is no quality or formatting difference on audio CDRs except junk they add to force you to buy them. ---
**Author:** ![KeithB](https://avatars.discourse-cdn.com/v4/letter/k/48db29/32.png) [@KeithB](https://boards.straightdope.com/u/KeithB)\ **Post date:** [September 28, 2001, 4:57pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/19 "2001-09-28T16:57:45Z")
My point exactly, mblackwell, I have paid for the right to make copies and now they are taking that away from me. AFAIK, Fenris, the CD’s have a hard-coded serial number or ID of somekind that the Audio CDR’s look for. If you put in a “data” recordable CD it will refuse to burn it. ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [September 28, 2001, 6:24pm UTC](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160/20 "2001-09-28T18:24:02Z")
> [@](#): > > And I predict this will be cracked within about…3 weeks after the CDs become widely distributed… - - - The CD-RW drive I bought has a link on their website to an (independent of the drive manufacturer) community CD-RW FAQ list on the web, which has a list of all available CD copying software, and states which anti-copy protections each is or isn’t capable of defeating. I find this rather humorous… ~ - Also, last time I looked (couple weeks ago) the FAQ said that nobody had cracked the Macrovision system yet or even been able to test it, because Macrovision had said that only one commercial disk had been distributed with it in eastern Europe, and wouldn’t name the disk. Neither Macrovision or any recording company would admit to using it on any disk. The FAQ also went into the reasons that it couldn’t be copyproof, and that if it did what they claimed it did it was capable of damaging PC CD drives, and it could very possibly damage ordinary stereo CD drives. - MC [Next page](https://boards.straightdope.com/t/how-does-the-new-cd-copy-protection-work/84160.md?page=2)