29 October 2021
CPRM (Content Protection for Recordable Media) is a copyright protection technology that makes it impossible to digitally copy digital broadcast video that is “recordable only once” to another recording medium after recording it on a DVD.
Video that is “recordable only once” of digital broadcasting can only be recorded on a DVD that supports CPRM. When dubbing the video recorded on the hard disk of the DVD recorder to DVD, the video on the hard disk is erased at the same time as dubbing to DVD. This mechanism records a key called “MKB” and identification information called “media ID” that is different for each DVD, and based on this information, the video data is encrypted and recorded, and the video is played back. Sometimes it’s decrypting. Therefore, even if you copy it to another DVD, it cannot be played because it cannot be decrypted correctly because the “media ID” of that DVD is different.
Currently, recording DVD-RAM, recording DVD-RW, and CPRM compatible DVD-R are CPRM compatible.