BD+ (BD plus) is a copy protection and digital rights management (DRM) of Blu-Ray discs. According to the procedure, a virtual machine (VM) is stored on the Blu-Ray discs, which is started by authorized BD players.
The virtual machine (VM) controls all functions with which the Blu-Ray disc is accessed. This includes unauthorized reading, changing the firmware, playing movies in unauthorized periods or after the expiration date and also possible manipulations on the BD-Player are controlled by this virtual machine. The user decides for himself which of these functions he wants to use.