Patent ID: 7730329
Filing Date: 2010-06-01
Classification: G06F

Abstract:
1. A method performed in combination with a device having a public-private key pair (PU-PD, PR-PD), the device for receiving a storage medium or having the storage medium, the storage medium having a public-private key pair (PU-PM, PR-PM) and having stored thereon digital content encrypted by a content key (KD) (KD(content)), a digital license corresponding to the digital content including (KD) encrypted by (PU-PM) (PU-PM(KD)), and a table including a plurality of entries therein, each entry including a random key (RND) encrypted by a (PU-PDx) of one of a plurality of devices (PU-PDx(RND)), each device having a public-private key pair (PU-PDx, PR-PDx) with a pre-selected index value x, the table further including (PR-PM) encrypted by (RND) (RND(PR-PM)), the method for the device to render the digital content on the storage medium and comprising: receiving a request to render the digital content on the storage medium; obtaining the table from the storage medium; obtaining (PR-PDx) and the index value x; indexing into an entry of the table based on the obtained index value x; obtaining (PU-PDx(RND)) from the indexed-into entry of the table; applying (PR-PDx) to (PU-PDx(RND)) to expose (RND); obtaining (RND(PR-PM)) from the table; applying (RND) to (RND(PR-PM)) to expose (PR-PM); obtaining (PU-PM(KD)) from the license; applying (PR-PM) to (PU-PM(KD)) to expose (KD); obtaining (KD(content)) from the storage medium; applying (KD) to (KD(content)) to expose the digital content; rendering the exposed corresponding digital content.