abstract:Device Keys play a role in the cryptographic key management procedure in the Advanced Access Content System (AACS) specification. This specification defines a method for protecting audiovisual entertainment content, including high-definition content.
The app will offer several other features, including a "Virtual Leash" that alerts you when the sticker goes out of range -- a "Reverse Virtual Leash" will make the device (perhaps attached to your keys) beep, letting you know you've left your smartphone behind.
By reading the encrypted data off of two cards and testing thousands of potential site codes against both cards until the decoded data displays a predictable interval between the two, he can find the site code and use it to create more card keys with a magnetizing device.