AACS

Advanced Access Content System (AACS) is the standard Digital Right Management (DRM) system for Blu-ray replicated discs (BDs). Each player is given a unique set of decryption keys. All players of a particular model are provided with the same shared decryption key. Whilst content is encrypted with a title-specific key, itself encrypted with each model's key. In this manner, each disc contains several hundred encrypted keys, one for each licensed player model. AACS utilises the Advanced Encryption Standard (AES) to encrypt content under one or more title keys. Title keys are obtained from a media key encoded in a Media Key Block (MKB) and the Volume ID of the media, a physical serial number embedded on a replicated Blu-ray disc. The Volume ID is stored in the BD-ROM Mark, a physical layer technology that embeds a unique identifier in pre-recorded ROM media discs. The BD-ROM Mark requires special equipment used in disc mastering available only to licensed BD-ROM replicators in order to be inserted on disc and thus, it prevents replications.

ACCS process

Clients wishing to replicate a BD title must have an ACCS Content Provider license obtainable from www.aacsla.com. With this, the replicator creates a master that is then submitted to AACS so that an encrypted master can be created and sent back to the replicator for mastering. The replicator then creates a stamper from the AACS-provided master that contains the replicators AACS Content Certificate and BD-ROM Mark, which can then be used for mass replication.