System and method for copying and moving content in a controlled manner between devices and domains based on conditional encryption of content key based on usage status

摘要

A method to move protected contents within an authorized domain (10), in which at least a first device (12) and a second device (13) are part of the authorized domain, sharing each of the devices (12, 13) that are part of the authorized domain a domain key, in which having the domain key defines the devices (12, 13) as part of the authorized domain, the method comprising the first device comprising: receiving from a content provider source external (50) an initial content key value and a content comprising a content ID, wherein the initial content key value and the content ID are associated with each other in a manner known to the content provider; create a content key operating on the initial value of the content key with the domain key of the first device; encrypt the content received with the content key; encrypt the content key with the domain key, so that all devices within the authorized domain have the ability to decrypt the content key encrypted with the domain key; create a certificate associated with the encrypted content, including the certificate the encrypted content key, the content ID, a record of usage states that sets the limits of reproduction in relation to the content, and the information that identifies the authorized domain; transmit the encrypted content and the certificate to the second device (13); and after transmitting the certificate, disable any certificate on the first device that is associated with said encrypted content.