Patent ID: 8225110

Claim:
A method of cryptographically protecting usage restrictions in an electronic device, comprising: cryptographically binding a software object to the device via digital signatures and a batch identification associating the device with one or more devices; cryptographically binding the software object to a secret cryptographic key via a hash of the secret key; cryptographically binding the secret key to a unique control key for each usage restriction by generating and storing a cryptographic footprint of the control key; cryptographically binding each control key to usage restriction settings defining the state and values of the usage restrictions by generating and storing a cryptographic message authentication code (MAC) of the usage restriction settings; and cryptographically verifying each of the bindings prior to changing any usage restriction setting; wherein cryptographically binding the secret key to a unique control key for each usage restriction by generating and storing a cryptographic footprint of the control key comprises generating the cryptographic footprints using a first device-specific key and the secret key in a first cryptographic function that atomically computes a hash of the secret key and then a message authentication code (MAC) of the hash of the secret key concatenated with a control key and associated data, using the first device-specific key, and storing the footprint.