Common Mathematical Locks
Please note that Mathematical Locks, when used as Copy Protection, (also called DRM) do not, and can not work. You would have to defeat cause and effect, which in turn allows things like trial and error.
Note that this list in incomplete. In particular, few user-friendly or neutral mathematical locks are listed.
- Advanced Access Content System
- Encryption scheme used in Blu-Ray and HD-DVD players. Due to the analog sunset clause in the AACS-LA
Final Adopter Agreement, players manufactured after December 31, 2010 are limited to DVD resolution on analog outputs. After December 31, 2013; no licensed player may be sold with analog outputs. Even if you are lucky enough to find an older player, individual titles may include an Image Constraint Token, giving DVD quality anyway. If your Blu-Ray Player is a PS3, be advised that Sony has a history of remotely removing features from the machine. I recommend sticking with DVD disks for the foreseeable future: DVD encryption does not support device revocation.
- Copy Protection for Recordable Media
- Originally proposed for hard-drives, this DRM scheme is included on writable DVD media endorsed by the DVD Forum. (I Have the check if DVD+R media (not endorsed by the DVD forum) includes CPRM) A slightly modified version including device revocation is included on all SD cards (I have to check what, exactly, happens upon device revocation.) I do not think it a coincidence that there are no good floppy replacements anymore. Without a write-protectable, DRM-free, relatively cheap, reasonably sized boot medium, computer restoration after an attack is complicated.
- Content Scrambling System
- Encryption scheme used on DVDs. Includes Region-coding; an all-digital format can technically be converted on-the-fly to different TV systems by the player itself. Even though this 40-bit (due to US export restrictions) encryption is famous for being broken, it may still be considered an
effective technological measure as specified in the 1996 WIPO treaties. Since January 1, 2000, region coding has been moved into drive firmware.
- Further reading:
- Digital Living Network Alliance
- Network stack for devices using DRM. UPnP is used for device discovery on the network and firewall piercing. This allows proprietary software to use Peer-to-Peer file transfer protocols in order to reduce server load. DTCP is used as
- Poorly defined, catch-all term to describe artificial restrictions placed on what you can do with digital files. May be applied to analog technologies like Macrovision in VHS VCRs as well. Some suggest calling DRM
Digital Restrictions Management instead.
- Digital Transmission Content Protection
- DTCP is a link-layer encrypted transport scheme. Included is a latency and hop limit (local networks only) as well as the transmission of
system renewability messages (device revocation).
- ePub 3.0
- Most common e-book readers support some kind of DRM. More information to follow.
- High-bandwidth Digital Content Protection
- Another link-layer encryption scheme intended primarily for display devices. Also includes device revocation. It is likely to be used in conjunction with the following ports: DisplayPort, DVI, and HDMI.
- Intel Insider
- Intel Insider - What Is It?
- Appears to be a modification of DTCP such that the latency restriction is removed to facilitate
broadcasting unicasting movies across the Internet. Decoding happens completely in the chipset, and presumably relies on DTCP or HDCP to get the video to a display device.
- DRM scheme included in some versions of Microsoft Office. It purports to be able to allow people to view documents without forwarding, printing or editing them. Since this violates the law of cause and effect, I believe this will lead to data breaches if institutions over-rely on it. Because these technologies are by definition proprietary, long-term data loss is a real possibility as well.
- Oracle Information Rights Management 11g
Back to James Phillips' personal website.
Are company-specific sections needed?
- Itunes is required for configuring their music players.
- Iphones, Ipads, and Ipads are locked-down. You are supposed to get even basic functionality from a walled garden known as the Apple store.
- DRM such as HDCP is creeping into their real computers as well.
- Their wireless routers only act as repeaters or wireless bridges if you are using an Apple-branded router as your main access point.
- Lexmark patented cartridges that be used only once in their printers. Cartridges are also region-coded. After trying to buy a Lexmark Laser printer, and returning it due to a
patent license printed on the box, I now think less of any store that would sell such a restrictive product without warning the customer.
- Microsoft writes the Operating system most commonly used in personal computers. They keep trying to branch out into other areas.
- PlaysForSure DRM scheme that is not supported by Microsoft's newer Zune DRM.
- Microsoft Genuine Advantage: interrogates computer to try to determine if you are using an authorized copy or not. Puts the computer into a
reduced functionality mode if it decides the installation is illegitimate.
- Windows Media Files may include DRM, including playback revocation.
- Protected Media Path: repeatedly re-encrypts video on the way to the display; disables analog outputs.
- Tried to tie cartridge playback to Trademark law by requiring games to display the Nintendo logo on load.
- Threatens to remotely 'brick' Nintendo 3DS consoles with 'unauthorized' modifications.
- Sony used to be cool; then they started purchasing entertainment companies.
- Digital Audio Tapes that copy only one generation. If you were recording your own material, you would have to keep the masters separate from the copies.
- BMG Rootkit fiasco. Sony was sued for installing malware when their CDs were played in a computer running Microsoft Windows.
- Sony remotely removes features from the PS3 console; formerly called a computer.
Edited: June 15, 2011.