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: The most interesting quantum thingy™ I'm aware of is Grover's algorithm, which seems to just magically be able to speed up some search-ish/brute-force things using magic.
gollark: Wait, so if I find a big prime number and use the `factor` command on it, I can actually say that my computer is outperforming leading-edge quantum computers at that task?
gollark: One day quantum computers might even be able to do useful things faster than my phone!
gollark: Still, it's a thing. Definitely a thing.
gollark: We've reached a point where quantum computers can do *some stuff* faster than classical ones, in that while it would be theoretically possible to emulate... Sycamore, or whatever it was, the one Google or someone had for "quantum supremacy" or something... on a supercomputer, it would take several days to do what it did in two minutes.

References


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