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I was reading the Wikileaks FAQ (archived here), it says:

Many CD and DVD writers will include the serial number of the DVD or CD writer onto the CD/DVDs they write. If the post is intercepted this information can in theory be used to track down the manufacturer and with their co-operation, the distributor, the sales agent and so on. Consider whether there are financial records connecting you to the CD/DVD writer sale if your adversary is capable of intercepting your letter to us and has the will to do this type of expensive investigation. Pay cash if you can for the CD/DVD writer.

Where is this number stored? Is it accessible in software by the device that wrote the CD?

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  • Do you want to get it programatically? If not, this question is better suited to SuperUser.
    – alex
    Nov 29, 2010 at 4:26
  • That'd be great. Nov 29, 2010 at 5:17
  • This is an interesting question. Favorited
    – abel
    Jan 19, 2011 at 15:50

3 Answers 3

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I've found reference to this on Wikipedia, starting from the section linked it describes two items that are placed on a disk:


Recorder Identification Code (RID)

Consists of a supplier code, a model number and the unique ID of the recorder.

This seems to be burnt on to the disk when it is written, and identifies the drive used - this is the code your quote is talking about.

However, I have been unable to find any specific details of implimentation...


Source Identification Code (SID):

Is an eight character code that is placed on every CD-ROM. The SID identifies not only manufacturer, the individual factory, and even the machine that produced the disc.

Quoting Philips: "The Source IDentification Code (SID Code) provides an optical disc production facility with the means to identify:

  • all discs mastered and/or replicated in its plant;
  • and the individual Laser Beam Recorder (LBR) signal processor or mould that produced a particular stamper or disc

Specifically, it looks like the SID code is stamped on when the disk is originally made, and not when you write the disk.

I managed to find a PDF file from Phillips, describing how manufacturers of CD should implement the SID code. From this we can see that the SID code are the numbers printed on the inner ring of the CD in the non-data area.

The SID code is therefore useful to identify fake or counterfeit products (but probably only to the authorities), because they will likely have the wrong SID code (the disks having been produced in a different factory to the real product).

Here is an example image of SID on a disk that I've found on the web:

Disk showing SID code

4
+500

This number is stored in the Q subchannel of the CD-R or CD-RW during the burning process, or in the main channel while the burning process starts (writing the PMA, which is the TOC for non-closed disc)

More info in the ECMA-394 standard PDF (this is an Orange Book excerpt, and freely available)

At page 9 :

Consumer CD-recorders shall write their Recorder IDentification (RID) code in subcode Q-channel mode 3

At chapter 5.2.3.1 :

Use of RID code in data applications

(optional, see also chapter 5.4.5) For Consumer CD-recorders the use of the RID code (Recorder IDentification code) in mode 3 of the Subcode Q-channel is mandatory in audio recordings (see chapter 5.6.3.2). Professional CD-recorders can store their RID code in the User Data field of all Run-in and Run-out blocks at each data recording action. The content of the User Data field of the Run-in and Run-out Blocks containing the RID code is defined in Figure 5-3.

At chapter 5.4.5 :

Professional CD-recorders, able to write the CD-ROM and/or the CD-i Format, shall write their RID code (see chapters 5.2.3.1 and 5.6.3.2.1 ) in the main channel of the Table Of Contents Items (subcode mode 1) in the PMA, whenever they record such an item.

Explanations :

  • The RID should be in the main channel in the PMA area of the CD-R/RW (an area way before the 00:00:00, thus unreadable using generic READ command)
  • The Run-in and Run-out blocks are sectors that are written when the writing laser is interrupted while burning the disc. TAO or Track-at-Once mode will generates those Run-in and Run-out blocks... but most firmware of consumers drives prevents READ command to read those blocks (since it's garbage).
  • If the CD-R/RW has been written by a Consumer CD-Recorder, the RID shall be written in the Q-channel in mode-3. But this is mandatory only if there is audio track.
  • The Q-channel can be read with any subchannel-extractor software but the RID seems not written in the main area… (I tried using homebrew software…)

You could extrapolate your drive RID (using "drive serial number" in any log of end-user cd-burning software and ECMA-394 chapter 5.6.3.2.1), but you cannot read a RID written on a CD-R/RW with the MMC-standard READ command used by software that wrote the CD.

edit : added some insights after a careful reading of the ECMA-394 standard

There is two kind of RID :

  1. The one written by a professional CD-recorder : the RID will be in the main channel of PMA and Run-in/Run-out blocks and shall include many details, see chapter 5.2.3.1 of ECMA-394 for details. This RID cannot be read using standard MMC commands.
  2. The one written by a consumer CD-recorder : the RID shall be in the Q-subchannel mode 3 in the main area, with much less detail. Mode 3 of Q-subchannel is usually for Track ISRC, which can be read by a standard MMC command called READ SUB-CHANNEL. The RID variant should not be returned by that command since the RID have a different bit pattern than ISRC. One will need to use the generic READ CD command and parse the answer.

To conclude, The RID wrote by a professional CD-recorder cannot be read with standard MMC commands. The RID wrote by a consumer CD-recorder could be read using standard MMC commands! But you will need a different software able to extract the whole CD subchannels (there is many), then another to decode the Q-subchannel from the extracted data, searching for mode 3 Q-subchannel frames, and hope that the CD-recorder added its RID here.

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  • It's not clear to me why the Q-channel which contains the RID can be written to with a CD-RW and not read from. Is this an assumed limitation of all firmware of CDRW? How does law enforcement and the like do it? Feb 3 at 22:30
  • 2
    This is not an assumed limitation, it is simply a non-existent command from the INCITS SCSI MMC standards. I believe there is non-standard command (aka vendor-specific) that allow you to read any area of a CD-R/RW using ATIP addressing, so law enforcement can read the PMA area and get the RID from here. Oddly, the INCITS standard has a command to read the RID in a DVDR, but not for a CDR ! Feb 4 at 22:21
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    I'm going to bounty this question just to award some rep to you. You've gave me the lingo I need for a follow up question. But this isn't the answer I'm looking for yet. Feb 5 at 1:26
  • 1
    Excellent late answer! The reputation reward is definitely justified. Feb 5 at 1:35
  • Here is my follow up question which is specific to Linux the operating system I use. unix.stackexchange.com/q/768531/3285 Feb 5 at 1:38
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For DVD-R family (but not +R apparently)

An identification for the drive which was used for burning a DVD is defined in ISO/IEC 23912 standard for recordable DVD media. This Unique ID Field is written in a specified area previous to the lead-in. The size of the Unique ID Field is 32 bytes for the manufacturer, 16 bytes for the serial number and 16 bytes for the model name.

That's cited to "Ecma International: 80 mm (1,46 Gbytes per side) and 120 mm (4,70 Gbytes per side) DVD Recordable Disk (DVD-R). In: Standard (2004), S. 7374" The +R has a different standard, by the way. It's not clear at all from the paper if the latter standard just doesn't account for that info at all, or what.

Wikipedia however says

Another distinction in comparison to DVD-R/RW/R DL is that the recorder information (optical drive model) is not written automatically to DVD+ discs by the drive. Nero DiscSpeed allows proprietarily adding such information for later retrieval.

(Presumably the latter software uses some proprietary format to add the info... somewhere.)

With a Plextor drive you can read that (for DVD-R/DVD-RW and the DL variants thereof, at least, but apparently not for the '+' variants, ie. not for DVD+R etc.) using the PxScan software [on Windows].

enter image description here

Also this is ancient software that may be hard to run on something other than XP, due to ASPI requirement, although the software's author reports running it ok on Vista via frogASPI.

Other software that does disc/burn quality check using chipset-specific commands (thus non-standard) may be able to read that RID info as well, because they rely on reading raw data, but I don't recall other software right now that advertised the (RID read) feature.

The Windows version of QPxTool also supports this, apparently with the same limitations drive and disc-wise.

enter image description here

I suspect the Linux version of QPxTool has the same features/limitations, but I cannot check quickly. From a screenshot on the site, one cannot read the writing-drive serial/mfg from DVD+R discs, at least from Linux (even on a Plextor drive), using that tool either.

enter image description here


As for CDs... only a very obscure piece of software, PLScsi, can apparently read that (and none of the above tools that can read the DVD id can do it for CDs.) And even that PLScsi only works for Plextor drives, but apparently all writers tested in that paper violate the CD standard and write a bogus serial number (to CDs), although the drive type was sometimes correct (but it seems to more often indicate the chipset).

PLScsi found the manufacturer’s code, the device type and the serial number. Often the serial number is 012345(hex). So only manufacturer and type are clearly ascertainable.

The table 2 shows the test results.

enter image description here

Additionally, in this study other programs like Subcode Analyzer, RID code, Nero Disk-Info, PxScan, CD/DVD Diagnostic, QPxTool, X-Ways, FTK and Encase were tested for the identification of the used burning hardware of a CD, but without results.

And an LG drive couldn't read any info at all even with PLScsi.

Some standalone hardware recorders, like TASCAM CD-RW402 also claim they can display the RID (for "drive 2" only--i.e. the [re]writable drive; "drive 1" is CD-ROM in that machine.)

The RID (recorder identification data), if present, can be shown for discs playing back on drive 2. Press the ERASE key while playback is taking place to display this data.

How well that works in practice is anybody's guess. But that manual usefully tells us how this info is presented/stored for CD's (it's more abbreviated than for DVDs):

The first three digits of the RID are assigned as the Manufacturer Code, the next four digits as the Type Code, and the last five digits as the Recorder Unique Number. TEAC’s Manufacturer Code is “TCJ”.

The DVD writer serial numbers however are typically much longer than that (as reported when they write DVD-R). So I guess that's why they [usually] punt and write a fictitious serial number in CD writing mode.

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  • Kprobe for the more common Mediatek chipsets doesn't seem to report that info (even with DVD-R discs) digitalfaq.com/images/kprobe.gif Feb 5 at 3:50
  • It seems that ImgBurn might also be able to read that info for DVD-R and reports it as "Recording Management Area Information", but I'm not sure on which drives specfically it can do that. Feb 5 at 7:06

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