# US 8,542,837 B2 · Key selection vector, mobile device and method for processing the key selection vector, digital content output device, and revocation list > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,837 B2 - Document ID: US8542837B2 - Status: Granted - Kind: B2 - Application number: 12/390,817 - Filed: 2009-02-23 - Published: 2010-08-26 - Granted: 2013-09-24 - Earliest claimed: 2009-02-23 - Assignees: Sony Corporation; Sony Mobile Communications Inc. - Applicants: Stefan Andersson; Per Gunnar Tobias Melin - Inventors: Stefan Andersson; Per Gunnar Tobias Melin - Web page: https://patentgrep.com/patent/US8542837B2 ## CPC - G09G 5/006: {Details of the interface to the display terminal (specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04)} - G09G 2370/04: Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller - G09G 2370/12: Use of DVI or HDMI protocol in interfaces along the display data pipeline - H04L 2463/101: applying security measures for digital rights management - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A key selection vector for a revocation list in an HDCP system as well as a mobile device and a method for processing a key selection vector, a digital content output device using a key selection vector and a revocation list for use in an HDCP system comprising a key selection vector are described. It is desired to improve handling of key selection vectors of revocation lists. A structured key selection vector for a revocation list is provided. The key selection vector is structured to contain at least one bit field with a predetermined number of bits and at a predetermined location in the key selection vector. The bit field contains information relating to a group property of a device, which group property allows to process as a group a plurality of key selection vectors storing the same or similar group property information in said at least one bit field. ## Claims ### Claim 1 A non-transitory storage medium storing computer readable instructions and a key selection vector for a revocation list in a high-bandwidth digital content protection (HDCP) system, wherein the computer readable instructions are executable by a processor to perform a method comprising: accessing the key selection vector containing at least one bit field with a predetermined number of bits and at a predetermined location in the key selection vector, wherein the bit field contains a first predetermined bit pattern relating to a group property of a device, identifying a plurality of key selection vectors storing same or similar group property information in said at least one bit field, wherein the key selection vector for the revocation list contains at least another bit field containing a second predetermined bit pattern which indicates that the key selection vector identifies said plurality of key selection vectors which are associated with a plurality of different devices, wherein the first predetermined bit pattern is included in a first bit field containing information relating to a first group property of a device and the key selection vector includes a second bit field containing information relating to a second group property of the device, and processing as a group key selection vectors storing same or similar first group property information irrespective of their second group property information. ### Claim 2 (depends on 1) The non-transitory storage medium of claim 1, wherein the key selection vector is assigned to said group using said group property information to speed up a search for a key selection vector among a plurality of key selection vectors. ### Claim 3 (depends on 1) The non-transitory storage medium of claim 1, wherein the at least one bit field contains group property information indicating at least one of a manufacturer identity, model identity, batch identity and unit identity. ### Claim 4 (depends on 1) The non-transitory storage medium of claim 1, further comprising processing as a sub group of key selection vectors storing the same or similar first group property information in the first bit field and storing same or similar second group property information in the second bit field. ### Claim 5 (depends on 4) The non-transitory storage medium of claim 4, wherein the first predetermined bit pattern relates to a predetermined first group property of a device and the second predetermined bit pattern indicates that all devices of said predetermined first group property related to said first predetermined bit pattern are to be revoked in an HDCP system irrespective of their second group property information. ### Claim 6 (depends on 1) A digital content output device for an HDCP system adapted to use the non-transitory storage medium storing the computer readable instructions and the key selection vector according to claim 1. ### Claim 7 (depends on 1) The non-transitory storage medium of claim 1, wherein a revocation list for use in an HDCP system is stored on the non-transitory storage medium. ### Claim 8 A mobile device adapted to process a key selection vector for a revocation list, comprising: a controller to control processing of key selection vectors in the mobile device, the controller being configured to selectively process as a group, based on a received key selection vector for a revocation list, a plurality of key selection vectors storing the same or similar group property information in the at least one bit field; and a memory to store key selection vectors; wherein: the received key selection vector is structured to contain at least one bit field with a predetermined number of bits and at a predetermined location in the received key selection vector, the bit field contains a first predetermined bit pattern relating to a group property of a device, which group property allows to process as a group a plurality of key selection vectors storing the same or similar group property information in said at least one bit field, said plurality of key selection vectors being associated with a plurality of different devices, and the key selection vector for the revocation list contains at least another bit field containing a second predetermined bit pattern which indicates that the key selection vector identifies said plurality of key selection vectors which are associated with a plurality of different devices, a receiving section to receive the revocation list containing the at least one key selection vector; wherein the controller is adapted to determine whether said received at least one key selection vector of said revocation list is stored in the memory and to discard all data of said revocation list except said at least one key selection vector if it is not stored in said memory. ### Claim 9 (depends on 8) The mobile device of claim 8, wherein said receiving section is configured to receive said revocation list from at least one of: a storage medium having said revocation list stored in it, a media file having said revocation list embedded in it, and a firmware upgrade. ### Claim 10 (depends on 8) The mobile device of claim 8, wherein said controller is adapted to process as a group the plurality of key selection vectors storing the same or similar group property information in the at least one bit field. ### Claim 11 (depends on 10) The mobile device of claim 10, wherein said controller is adapted to process as a group key selection vectors storing same or similar first group property information in the first predetermined bit pattern irrespective of second group property information stored in the second predetermined bit pattern. ### Claim 12 (depends on 11) The mobile device of claim 11, wherein said controller is adapted to process as a sub group key selection vectors storing the same or similar first group property information in the first predetermined bit pattern and storing same or similar second group property information in the second predetermined bit pattern. ### Claim 13 A method for processing a key selection vector for a revocation list by a mobile device including a processor, the method comprising the steps of: receiving a revocation list containing at least one key selection vector, the at least one key selection vector structured to contain at least one bit field with a predetermined number of bits and at a predetermined location in the key selection vector; wherein the bit field contains a first predetermined bit pattern relating to a group property of a device, which group property allows to process as a group a plurality of key selection vectors storing the same or similar group property information in said at least one bit field, said plurality of key selection vectors being associated with a plurality of different devices; and wherein the key selection vector for the revocation list contains at least another bit field containing a second predetermined bit pattern which indicates that the key selection vector identifies said plurality of key selection vectors which are associated with a plurality of different devices; and selectively processing as a group, based on the key selection vector in the revocation list, the plurality of key selection vectors storing the same or similar group property information in the at least one bit field using the processor; determining whether said received at least one key selection vector of said revocation list is stored in a memory; and discarding all data of said revocation list except said at least one key selection vector if it is not stored in said memory. ### Claim 14 (depends on 13) The method of claim 13, further comprising the step processing as a group key selection vectors storing same or similar first group property information in a first bit field irrespective of second group property information stored in a second bit field; and processing as a sub group key selection vectors storing the same or similar first group property information in the first bit field and storing same or similar second group property information in the second bit field. ### Claim 15 (depends on 13) A non-transitory storage medium storing a computer program product, which when loaded into program memory of a processor or microcontroller, causes the processor or microcontroller to carry out a method of claim 13.