Patent ID: 8307460

Claim:
A method of obtaining content information in an environment where a Digital Rights Management (DRM) agent and a rendering application are separated from each other, the method comprising: transmitting, by a consumer electronics (CE) device comprising the rendering application, first N bytes of the content to a portable Digital Rights Management (PDRM) device comprising the DRM agent; and obtaining, by the PDRM device, information about the content by using a cryptographic hash with respect to the first N bytes, and transmitting the obtained information to the CE device, wherein a number of bytes of the entire content is greater than a number of bytes of the first N bytes, wherein initially transmitting the first N bytes from the CE device to the PDRM device, further comprises: transmitting, by the CE device, the content to the PDRM device upon a request of the PDRM device; obtaining, by the PDRM device, a content identifier of the content by using the content; and creating a hash entry by mapping the cryptographic hash of the content with the content identifier, maintaining, by the PDRM device, a hash map table; and updating the hash map table to include the created hash entry; wherein the obtaining and the transmitting is performed when the CE device subsequently transmits the first N bytes to the PDRM device, and obtains information about the content by using the updated hash map table, analyzing, by the PDRM device, the subsequently transmitted first N bytes to verify whether the subsequently transmitted first N bytes are sufficient to calculate the cryptographic hash; requesting the CE device for bytes required to calculate the cryptographic hash when the subsequently transmitted first N bytes are insufficient; and transmitting, by the CE device, the required bytes to the PDRM device when the request is received from the PDRM device.