Digital rights management (DRM) encryption and data-protection for content on device without interactive authentication
AssigneeMicrosoft Corporation
InventorsClifford Strom, Krishnamurthy Ganesan, Jonas Helin
Life of this patent
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Abstract
To render content on a medium, a device obtains a table from the medium, obtains a private key of the device (PR-PD), indexes into an entry of the table based thereon, obtains (PU-PD(RND)) from the indexed-into entry of the table, and applies (PR-PD) to (PU-PD(RND)) to expose a random key (RND). Then, the device obtains (RND(PR-PM)) from the table, applies (RND) to (RND(PR-PM)) to expose a private key of the medium (PR-PM), obtains (PU-PM(KD)) from the license, applies (PR-PM) to (PU-PM(KD)) to expose a content key (KD), obtains (KD(content)) from the storage medium, applies (KD) to (KD(content)) to expose the content.
Claims28
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 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-PD) of one of a plurality of devices (PU-PDx(RND)), the table further including (PR-PM) encrypted by (RND) (RND(PR-PM)), the method for the device to render the content on the medium and comprising:
- receiving a request to render the content on the medium;
- obtaining the table from the medium;
- obtaining (PR-PD);
- indexing into an entry of the table based on the obtained (PR-PD);
- obtaining (PU-PD(RND)) from the indexed-into entry of the table;
- applying (PR-PD) to (PU-PD(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 content;
- and
- rendering the exposed corresponding content.
(canceled)
7-8. (canceled)
A method performed in combination with a host computer and a plurality of devices each having a public-private key pair (PU-PD, PR-PD), each device for receiving a storage medium or having the storage medium, the storage medium including an ID thereof thereon and having a public-private key pair (PU-PM, PR-PM) and for having stored thereon digital content encrypted by a content key (KD) (KD(content)), a digital license corresponding to the 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-PD) of one of a plurality of devices (PU-PD(RND)), the table further including (PR-PM) encrypted by (RND) (RND(PR-PM)), the method for the host computer to provide the medium with the table and comprising:
- obtaining the table from a cache;
- obtaining the ID of the medium therefrom;
- appending the obtained ID of the medium to the obtained table;
- employing a (PR-PD) to find the corresponding entry in the obtained table and expose (RND);
- tying the table to the medium by the ID of the medium and (RND);
- and
- copying the tied table to the medium.
(canceled)
15-20. (canceled)
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 content including (KD) encrypted by (PU-PM) (PU-PM(KD)), and a table including a plurality of entries therein, each entry including (PR-PM) encrypted by a (PU-PD) of one of a plurality of devices (PU-PD(PR-PM)), the method for the device to render the content on the medium and comprising:
- receiving a request to render the content on the medium;
- obtaining the table from the medium;
- obtaining (PR-PD);
- indexing into an entry of the table based on the obtained (PR-PD);
- obtaining (PU-PD(PR-PM)) from the indexed-into entry of the table;
- applying (PR-PD) to (PU-PD(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 content;
- and
- rendering the exposed corresponding content.
(canceled)
27-28. (canceled)
A method performed in combination with a host computer and a plurality of devices each having a public-private key pair (PU-PD, PR-PD), each device for receiving a storage medium or having the storage medium, the storage medium including an ID thereof thereon and having a public-private key pair (PU-PM, PR-PM) and for having stored thereon digital content encrypted by a content key (KD) (KD(content)), a digital license corresponding to the content including (KD) encrypted by (PU-PM) (PU-PM(KD)), and a table including a plurality of entries therein, each entry including (PR-PM) encrypted by a (PU-PD) of one of a plurality of devices (PU-PD(PR-PM)), the method for the host computer to provide the medium with the table and comprising:
- obtaining the table from a cache;
- obtaining the ID of the medium therefrom;
- appending the obtained ID of the medium to the obtained table;
- employing a (PR-PD) to find the corresponding entry in the obtained table and expose (PR-PM);
- tying the table to the medium by the ID of the medium and (PR-PM);
- and
- copying the tied table to the medium.
(canceled)
35-40. (canceled)
Dependencies are inferred from the claim text.