There is many media attention lately about a new copy protection build in recordable media, like harddisks. The Register has an article about wich explains it very well, so if you're intrested in how it works read on...
1. What is CPRM?
CPRM or Content Protection for Recordable Media is a mechanism for controlling the copying, moving and deletion of digital media on a host device, such as a personal computer, or other digital player. It's already used in specific removable media, and is now being proposed for inclusion in the ATA specification, for hard drives.
Each CPRM-compatible ATA hard drive is individually signed, and authenticates the playback and movement of files on the device against a central server using CPRM-compliant software.
2. Is CPRM going to go into hard drives? Has this already happened? If it hasn't, will it happen?
The NCTIS T.13 committee, which sets the ATA hard disk standard, will meet for the third time to debate a proposal to extend the ATA command set to include CPRM in February. The proposal is "optional": devices may include CPRM and be deemed "compliant" with the ATA specification, but not have CPRM available to client software.
3. How does this "break" existing software?
In itself, it doesn't. Several things must happen. The hardware must be CPRM-compliant, and have CPRM activated in the firmware by the manufacturer, and the user must then download CPRM-ready media, such as audio files or documents, using CPRM-compliant software. The media downloaded must also have restrictions placed upon its reproduction - but then, that's the whole point of protecting files with CPRM isn't it?
The user must also have the keys - or access to the keys - when the signed media is moved, or copied or deleted. Downloaded media is associated with an individual drive, so if you can't produce the keys, then restore operations will fail. If you can't produce the keys, then RAID software will break. If you can't produce the keys, file optimisation and disk defragmenters will be unable to move the blocks used by the media. If you can't produce the keys, one-to-many imaging programs will break...
4. So this means I'll be able to sign application binaries, or entire software distributions, to prevent unauthorised duplication?
Yes
Read the full article here!
