Data position measurement

Data position measurement (DPM) is a copy protection mechanism that operates by measuring the physical location of data on an optical disc. Stamped CDs are perfect clones and always have the data at the expected location, while a burned copy would exhibit physical differences. DPM detects these differences to identify user-made copies. DPM was first used publicly in 1996 by Link Data Security's CD-Cops. It was used in volume on Lademans Leksikon published by Egmont in November 1996.

RMPS

DPM can be observed and subsequently encoded into a recordable media physical signature (RMPS). In concert with emulation software RMPS can reproduce the effects of DPM thereby appearing as an original disc and fooling the protection mechanism. This technique was pioneered by the software Alcohol 120%, for which it created the .mds file format.

gollark: Oh, for IO, neat. I wonder why that hasn't really taken off yet.
gollark: Unless you count whatever "silicon photonics" stuff Intel is doing for 400GbE and such.
gollark: Delayed again? I don't think the technology exists at all now.
gollark: 3nm and below will apparently use GAAFETs, which are a new design of transistor which will improve things somewhat.
gollark: Bottom of the range dedicated GPUs are (still) £30 or so.

References


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