2

I know there were no such hacks observed. But if we consider case of corporate attack (firmware virus created by ROM device producing corporation itself) on privacy of a person.

Would it be possible in such scenario to rewrite DVD-R and other kinds of non rewritable disks? Or is this impossible because of physics of the process (provide a link to proof please) or is it impossible because of non programmable chip on disk reader circuit?

Kevin Panko
  • 7,346
  • 22
  • 44
  • 53
Vyacheslav
  • 235
  • 2
  • 4
  • 9
  • 2
    If the disc burn has be finalized, then no, if the disc was Not finalized then yes it can be modified by another burning session. – Moab Jun 08 '15 at 15:17
  • I asked [more specific question](http://superuser.com/questions/925422/is-it-possible-to-modify-once-recorded-cd-r-dvd-r-bd-r-on-bit-level). Maybe it's what you meant, OP. – Kamil Maciorowski Jun 08 '15 at 21:44

1 Answers1

4

Is it possible to rewrite CD-R, DVD-R, Bluray-R discs?

They cannot be rewritten.

Recording on DVD-R discs is accomplished through the use of a dye recording layer that is permanently transformed by a highly focused red laser beam.


Recording on DVD-R discs is accomplished through the use of a dye recording layer that is permanently transformed by a highly focused red laser beam. This dye substance is spin-coated onto a clear polycarbonate substrate that forms one side of the body of a complete disc. The substrate is injection moulded, and has a microscopic, pre-grooved spiral track formed onto its surface. This groove is used by a DVD-R drive to guide the recording laser beam during the writing process, and also contains recorded information after writing is completed. An undulating wobble signal is moulded into the pre-groove for synchronising a DVD-R drive’s spindle motor during the writing process, and Land Pre-Pits (LPP) are also contained in the land areas between grooves for addressing purposes. A thin layer of metal is then sputtered onto the recording layer so that a reading laser can be reflected off the disc during playback. A protective layer is then applied to the metal surface, which prepares the side for the bonding process.

Source DVD-R – write once recordable DVDs

DavidPostill
  • 153,128
  • 77
  • 353
  • 394
  • I have doubts. As far as I understand, the laser leaves permanent "ones" on the disk. But parts that are supposed to be "zeros" are left untouched (meaning that a "virgin" DVD-R would be read as stream of zeros). Meaning that they can still be burned and thus turned into "ones". So a malicious actor could still damage data on DVD-R, by rewriting "virgin" bits with ones. And it's how "E-hammer" software from ASUS works. – KarmaPeasant Jan 30 '23 at 11:39