Media Key Block

The system was developed by companies from the film industry and the electronics industry including IBM, Intel, Microsoft, Matsushita (Panasonic), Sony, Toshiba, The Walt Disney Company and Warner Bros.

Even though it seems a simple mechanism the MKB key which is found in the physical support of the disc follows a complex structure.

The MKB itself is found inside the field Media Key Data Record and has a variable length but it is always a multiple of 4 bytes.

[3] Many consumer associations have complained against this system since it can lead to a situation where physical devices cannot reproduce contents even though they do not infringe any intellectual property.

This situation has become even worse with the recent publication in multiple web sites of the Media Key, that is, the key that allows decrypting the Volume ID[4] and at the same time, the encrypted content, without the need of using a certified device by the AACS or a valid MKB.

This is especially critical because nowadays the Volume ID is the same in all the Blu-ray or HD-DVDs with equal content.