Content Protection for Removeable Media. A very, very similar scheme. It's present in all Secure Digital cards: That's what the 'secure' part indicates. It just isn't used by anyone. Ever. An abandoned DRM scheme. The demand wasn't there, as commercial sales of content on SD card never took off, and hardware players all went with competing methods based on tying files in some manner to devices rather than media. There was no interest in media-tying, because the only advantage that could give would be in allowing users to re-sell their purchased media second-hand. A feature content suppliers actively opposed.
If you remember a big panic a few years back about DRM being built into hard drives, CPRM was the technology being panicked over.