The Advanced Access Content System (AACS) is a digital rights management (DRM) and copy protection technology used primarily for safeguarding the content distributed on Blu-ray discs and some HD DVDs. AACS is designed to prevent unauthorised copying, distribution, and playback of copyrighted material stored on optical discs.
AACS is a fundamental part of the content protection system used in Blu-ray discs. Despite efforts to secure content, DRM systems like AACS have faced challenges from individuals or groups attempting to bypass or circumvent the protection measures. Hackers have sometimes successfully compromised AACS encryption, leading to concerns about piracy.