I am wondering if there is a way to tie a particular burned cd to a particular cd recorder?
For example, I have TWO CD recorders of different makes and models (brand A and brand B) on two different PC's, and I have two blank CD's from the same manufacturer, type, and model number, cd1 and cd2.
Suppose I record a few minutes of music onto cd1 using brand A recorder. Now I make a copy of cd1 onto cd2 using brand B cd reader/recorder on the second PC.
Normally, one would think that these two cd's would be identical, and there would be no way to tell which one was recorded using brand A recorder or brand B recorder.
However, reading about the physical aspects of cd creation, we see that there are "pits" and "lands" on the cd's which constitute methods of reflecting laser light so that a light diode will detect a difference in intensity, sufficient to indicate a "0" or a "1", depending on whether or not there was a change from land to pit, pit to land, or no change, and that an exact copy (digital-wise) that has the exact same zeroes and ones might have a slightly different pattern of lands and pits, and, that the degree of light deflection from the "burned" pits could also vary between the two recorders.
If one could build/acquire/invent such an instrument, one might find that recorder A would make pits that reflect the laser light by a detectable different degree than recorder B, even though the net result of both would be the same binary value (0 or 1). Also, isn't it likely that the exact radial distance from the center of the cd to where the first burning occurs might vary slighty from recorder to recorder.
In these ways, one might be able to discover which recorder made which CD by examining the exact radial distance that the burning begins, and the variations in the "burning" of the pits and lands that would escape any ordinary digital reading of either CD.
Is this thinking off base? If so, does anyone have any knowledge as to how a forensic expert could match a given recorder to a given CD - or, conversely, can an expert determine that a particular burned CD was NOT burned by a particular recorder?
If I'm not mistaken, you will sometimes find a serial number of the device in the session metadata.
Is this thinking off base?
Hell no! Darn good question! I'll be sitting back and look forward to some of the experts chime in.
"Recorder Unique IdentifierOwing to pressure from the music industry, as represented by the IFPI and RIAA, Philips developed the Recorder Identification Code (RID) to allow media to be uniquely associated with the recorder that has written it. This standard is contained in the Rainbow Books. The RID-Code consists of a supplier code (e.g. "PHI" for Philips), a model number and the unique ID of the recorder. Quoting Philips, the RID "enables a trace for each disc back to the exact machine on which it was made using coded information in the recording itself. The use of the RID code is mandatory." [5] Although the RID was introduced for music and video industry purposes, the RID is included on every disc written by every drive, including data and backup discs.
Source IDentification CodeThe Source IDentification Code (SID) is an eight character supplier code that is placed on every CD-ROM. The SID identifies not only manufacturer, the individual factory, and even the machine that produced the (blank, writeable) disc.
Quoting Philips "The Source IDentification Code (SID Code) provides an optical disc production facility with the means to identifyall 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."
[5]
Use of RID and SID together in forensicsThe standard use of RID and SID mean that each disc written contains a record of the machine that produced a disc (the SID), and which drive wrote it (the RID). This combined knowledge may be very useful to law enforcement, to investigative agencies, and to private and/or corporate investigators. [6]"
I am wondering if there is a way to tie a particular burned cd to a particular cd recorder?
If the recorder writes RID information, yes.
Home audio equipment must do so. For professional equipment and data recorders it is optional, but it may still be present – several NEC and Philips CD-R recorders include it, for example.
(Added I just see that ECMA published ECMA-394 late last year "Recordable Compact Disc Systems CD-R
Multi-Speed". The various quotes I have collected from Club MyCE on RID codes from the Orange Book can be found in this document, so I suspect it's substantially the same as the Orange Book. All (?) ECMA standard – which includes many ISO standard texts – can be downloaded free from ecma-international . com . )
(Added even later and after perusing that standard, I'm no longer sure I am right in my earlier belief that recording RID is optional for data applications.)
I have no idea if the method you suggest is reasonable or practical. Don't forget, though, CD-R media contain 'Special Information 1' fields, which contains 'suggested write power', so write power may not be quite as stable as you may hope (I have that from the SCSI MMC standard document, which also contain lots of information on CD-related media) – and may possibly change on flash upgrades.
But in practice it is quite rare to find CD/DVD writers that do write the RID-code when writing data, which was mainly aimed to "Audio CD recorders".
The "new" standard seems like using the same approach.
Compare with
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P.S. Sorry athulin, cross-posting
If I'm not mistaken, you will sometimes find a serial number of the device in the session metadata.
I've only ever seen this information on DVDs and not CDs