Encrypted Title Key

The content stored in medias like Blu-ray or HD-DVDs is composed and divided in information units called Titles.

[1] To codify the Encrypted Title Key, a codification is made following the next formula: AES-128E (Kvu, Kt ⊕ Nonce ⊕ AES_H(Volume ID || title_id)) It is possible to demonstrate, with a simple analysis of the formula, that the result is obtained of a combination between the Volume ID and a Title identifier obtained from the Media Key, giving as a result the Kvu (Volume Unique Key).

If any recorder discovers a temporary MKB on a piece of media, it is an indication that the encrypted Title Keys might be corrupted.

Which protocol is chosen depends on where the encrypted Title Keys are stored in the particular application.

A device re-encrypting Title Keys as a normal result of updating a recordable MKB shall also use these same protocols.

The Encrypted Title Keys are located in the Blu-ray and HD-DVDs where there is content to reproduce by the player with license.

Process to obtain the Media key , from the MKB and the Device Keys
decrypted AACS process
Components localization in the disc media