TCG Opal

Overview

TCG Opal is a Trusted Computing Group storage security class that models everything as tables and objects. It maintains an AES-256 table of key objects whose use by the drive's AES engine is gated by the locking table's read-locked and write-locked states: if either state is disabled, access to the media encryption key (MEK) is required to perform the corresponding read or write operation. The AES-256 table links to the locking table through the active key column within the locking object, connecting a key to the address range it secures.

As of the 2025 OCP Global Summit storage talk, the TCG Opal spec was finalized and released as version 1.0, available for download. It serves as the foundation that the MEK-MPA feature set extends — MEK-MPA adds access conditions on top of Opal rather than replacing any of its existing mechanisms.