Hi...
I've seen much confusion about Sony's newest creation, SecuROM v4.8x, so I'm going to try and unravel some of the legends about this.
Most copy protections are based on recognizing a copy from an original CD. E.g. Safedisc does this by checking for defect sectors on the disc that are hard to copy. But those defect sectors can already be copied, so Safedisc doesn't deliver full protection against copying anymore.
SecuROM v4.8x goes another way, and this way looks very promising right now. The spiral data track on the disc has a varying structure which causes the drive to take more or less time to read a sector. These delays between the delivery of two sectors is checked, and if the delays do not fit the right pattern, the CD is recognized as invalid.
Unfortunately it is impossible to copy this structure because the spiral data track is already pressed into a CDR when you buy it. Inside this track there is a substance that changes when it is hit by the writing laser, so the bits and bytes can be burnt into the track. But it is impossible to manipulate one sector so it takes longer to read it so a CDR will always be recognized as invalid.
However it is possible to monitor these delays and write them down in a file - and this is exactly what tools like Alcohol 120% and Blindread do. In Alcohol, this feature is called DPM - Data Positioning Measurement. The information gained from the DPM process is stored in the .mds-files (but not alone, there can be .mds-files without DPM information as well) (in Blindwrite, it is stored in .bwa-files which are exactly the same). With the virtual drives created by Alcohol (as well as with Daemon-Tools' virtual drives) it is now possible to emulate these delays when the image is mounted. And this will be the only working way to make backups as long as the spiral data track's structure cannot be manipulated.
Conclusion of the above-said:
It will not be able to make working 1:1 copies of SecuROM v4.8-protected CDs anymore.
Mounting images and emulating the copy protection will be the way to go.
Now many of you may ask what about Blindwrite as it does make working copies of SecuROM v4.8-protected CDs.
That is correct, but read exactly what I wrote: it is possible to make working copies, but NOT working 1:1 copies!
Blindwrite uses the information stored in the .bwa-files (which, as we remember, tells how long it takes to read a sector on the disc). Now it uses a trick to "fake" this reading delay - the same sector is burned twice onto the disc, with exactly the same information including the sector number. This is a violation of the CDR-standard (the so-called orange book, if I recall correctly), but as most CD-drives read both sectors but only deliver one, the delay of reading the second sector suffices to trick SecuROM v4.8x into recognizing the disc as valid. However some drives, e.g. some Plextors, report errors if the same sector is stored twice on the disc. As this is a violation of the standards, this is nothing negative, in fact this only happens with drives who strictly obey the standards.
The drawback of this method is that today's copyprotections (i.e. SecuROM) can easily be altered to check for these manipulations, too. So this ability to copy SecuROM v4.8x will most certainly not last very long, and if you're unlucky, your copy will become invalid with the next patch for the game because the patch will also update the copy protection (like No One Lives Forever 2 v1.2, Anno 1503 v1.02, Neverwinter Nights 1.21...)
Well, I guess that pretty much sums up my knowledge about SecuROM v4.8x. Most of the information comes from the author of Daemon-Tools so I think it can be regarded rather accurate... which is not meant to be understood as a praise of myself but rather of him.
Hope it helps...
Sergei
I've seen much confusion about Sony's newest creation, SecuROM v4.8x, so I'm going to try and unravel some of the legends about this.
Most copy protections are based on recognizing a copy from an original CD. E.g. Safedisc does this by checking for defect sectors on the disc that are hard to copy. But those defect sectors can already be copied, so Safedisc doesn't deliver full protection against copying anymore.
SecuROM v4.8x goes another way, and this way looks very promising right now. The spiral data track on the disc has a varying structure which causes the drive to take more or less time to read a sector. These delays between the delivery of two sectors is checked, and if the delays do not fit the right pattern, the CD is recognized as invalid.
Unfortunately it is impossible to copy this structure because the spiral data track is already pressed into a CDR when you buy it. Inside this track there is a substance that changes when it is hit by the writing laser, so the bits and bytes can be burnt into the track. But it is impossible to manipulate one sector so it takes longer to read it so a CDR will always be recognized as invalid.
However it is possible to monitor these delays and write them down in a file - and this is exactly what tools like Alcohol 120% and Blindread do. In Alcohol, this feature is called DPM - Data Positioning Measurement. The information gained from the DPM process is stored in the .mds-files (but not alone, there can be .mds-files without DPM information as well) (in Blindwrite, it is stored in .bwa-files which are exactly the same). With the virtual drives created by Alcohol (as well as with Daemon-Tools' virtual drives) it is now possible to emulate these delays when the image is mounted. And this will be the only working way to make backups as long as the spiral data track's structure cannot be manipulated.
Conclusion of the above-said:
It will not be able to make working 1:1 copies of SecuROM v4.8-protected CDs anymore.
Mounting images and emulating the copy protection will be the way to go.
Now many of you may ask what about Blindwrite as it does make working copies of SecuROM v4.8-protected CDs.
That is correct, but read exactly what I wrote: it is possible to make working copies, but NOT working 1:1 copies!
Blindwrite uses the information stored in the .bwa-files (which, as we remember, tells how long it takes to read a sector on the disc). Now it uses a trick to "fake" this reading delay - the same sector is burned twice onto the disc, with exactly the same information including the sector number. This is a violation of the CDR-standard (the so-called orange book, if I recall correctly), but as most CD-drives read both sectors but only deliver one, the delay of reading the second sector suffices to trick SecuROM v4.8x into recognizing the disc as valid. However some drives, e.g. some Plextors, report errors if the same sector is stored twice on the disc. As this is a violation of the standards, this is nothing negative, in fact this only happens with drives who strictly obey the standards.
The drawback of this method is that today's copyprotections (i.e. SecuROM) can easily be altered to check for these manipulations, too. So this ability to copy SecuROM v4.8x will most certainly not last very long, and if you're unlucky, your copy will become invalid with the next patch for the game because the patch will also update the copy protection (like No One Lives Forever 2 v1.2, Anno 1503 v1.02, Neverwinter Nights 1.21...)
Well, I guess that pretty much sums up my knowledge about SecuROM v4.8x. Most of the information comes from the author of Daemon-Tools so I think it can be regarded rather accurate... which is not meant to be understood as a praise of myself but rather of him.
Hope it helps...
Sergei
