Blu-ray discs are here to supersede DVD in every way, be it quality of picture (1080p), interactivity (BD-J), size (50Gb) and now protection.
Conventionally the DVD used CSS (content scrambling system) as its encryption, although mediocre, the development of a new encryption would have been time consuming and would have caused delays. Hackers decrypted the system in little time inducing a loss of billions. The main decryption known today is DeCSS created by Jon Lech Johanssen (alias DVD jon), who proclaims in his defence that he simply wanted to back up his own collection of legally purchased DVD.
Initially Blu-ray was introduced by Sony as a larger recording media for back up purposes but as there was demand for high definition movies that required high capacity media, the amalgamation of the two was inevitable. Having learnt from the mistakes of CSS a better encryption method was needed.
AACS (advanced access content system) jointly developed by Sony, Toshiba, Warner, Panasonic, IBM, Microsoft and Intel will be used with both HD-DVD and Blu-ray. This system can stop a device from playing any more movies causing it to be useless. This is done if the machine is hacked to perform an illegal rip. What AACS can do is disable the decryption keys unique to that device. AACS also incorporates an image constrain token (ICT); this applies to analogue video outputs downgrading the HD video signal to a maximum resolution of 960 x 540. ICT is only an option for the video content owner. An audio watermark is another feature of AACS again being optional to the video content owner which is an inaudible signal inserted into the audio track.
In addition to AACS the Blu-ray association have decided to add another two layers to the BD-ROM the ROM-Mark and the BD+. The latter is something we will discuss later.
The ROM-mark is another layer added to the protection of the disc from pirates. It is an analogue level mechanism of bit-by-bit copy protection and will be embedded in pre-recorded ROM media such as movies, music and games. The ROM-mark is invisible to the consumer and requires special Blu-ray manufacturing equipment to be created.
BD+ is a variant of a technology called self-protecting digital content (SPDC). This provides dynamic renewable protection. Title specific code is extracted from the disc and embedded into a virtual machine, security software checks are done by the disc to secure its own playback. Inevitably what this does is allows video content providers to renew content protection on BD-ROM players which have been hacked.
The future of Blu-ray protection is important and imperative in an age of hackers. Their philosophy at getting back at the big movie corporations and their rip-off to consumers not surprisingly has the majority vote with people who want to pay less.