# US 11,451,846 B2 · Pre-entitlement enforcement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,846 B2 - Document ID: US11451846B2 - Status: Granted - Kind: B2 - Application number: 17/358,789 - Filed: 2021-06-25 - Published: 2021-10-21 - Granted: 2022-09-20 - Earliest claimed: 2017-05-05 - Assignees: Nagravision S.A. - Applicants: Nagravision S.A. - Inventors: Didier Hunacek; Jean-Bernard Fischer - Web page: https://patentgrep.com/patent/US11451846B2 ## CPC - H04N 21/26606: {for generating or managing entitlement messages, e.g. Entitlement Control Message [ECM] or Entitlement Management Message [EMM] (arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14)} - H04N 7/1675: {Providing digital key or authorisation information for generation or regeneration of the scrambling sequence (pseudo-random number generators in general G06F7/58)} - H04N 21/235: Processing of additional data, e.g. scrambling of additional data or processing content descriptors - H04N 21/4181: {for conditional access} - H04N 21/4623: Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] {(arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14)} - H04N 21/63345: {by transmitting keys (key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06)} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method of transmitting entitlement messages to content consumption devices in a access control system, the method comprising periodically transmitting entitlement messages to content consumption devices in a access control system and periodically extending an expiry time comprised in the entitlement messages. The entitlement messages comprise indicator data indicating to the content consumption devices that subsequent entitlement messages loaded into a content consumption device after a first entitlement message is loaded into the content consumption device shall not be used by the content consumption device to access protected media content. ## Claims ### Claim 1 An access control module comprising: circuitry configured to: receive a first entitlement message, which is a security message transmitted periodically, wherein the first entitlement message comprises entitlement data comprising an expiry time, access data enabling access to protected media content until the expiry time and an indicator data, determine whether an entitlement message is a first received entitlement message by verifying if entitlement data has already been stored, and in response to a positive determination store entitlement data and the indicator data of the first entitlement message into a memory, receive access information comprising a current time and a descrambling key, compare the current time with the expiry time and decrypt the descrambling key with a decryption key of the access data, and grant access to the protected content in response of a positive comparison, receive a subsequent entitlement message, update the expiry time stored in the memory with the expiry time included in the subsequent entitlement messages if the subsequent entitlement message indicator data of the subsequent entitlement message is at least the same of the stored indicator data, and reject the subsequent entitlement message otherwise. ### Claim 2 (depends on 1) The access control module according to claim 1, wherein the entitlement data includes an identifier specific to the expiry time. ### Claim 3 (depends on 2) The access control module according to claim 2, wherein the circuitry is further configured to: store verification data enabling data enabling verification of the identifier in a one-time programmable memory; prior to using entitlement data to access media content, determine if the identifier of the entitlement data matches the verification data; and prevent use of the entitlement data to access media content if the identifier of the entitlement data does not match the verification data. ### Claim 4 (depends on 3) The access control module according to claim 3, wherein the circuitry is further configured to: irreversibly physically alter the one-time programmable memory when storing data in the one-time programmable memory. ### Claim 5 (depends on 3) A content consumption device comprising: the access control module according to claim 3; a receiver to receive protected content and entitlement messages; a descrambler to descramble the protected content using control data derived from the access data; and a video processor to generate a video signal from the descrambled content. ### Claim 6 (depends on 1) The access control module according to claim 1, wherein the circuitry is further configured to store the entitlement data in volatile memory. ### Claim 7 (depends on 1) The access control module according to claim 1, wherein the circuitry is further configured to: store the entitlement data in a one-time programmable memory; and prevent use of entitlement data comprising indicator data not stored in the one-time programmable memory. ### Claim 8 (depends on 1) The access control module according to claim 1, wherein the circuitry is configured to: determine, at the time of receiving the entitlement data, if the received entitlement data was received after previous entitlement data comprising indicator data has been stored in the access control module; and prevent storing of or to delete the entitlement data in response to the determination if the determination is affirmative. ### Claim 9 An access control method, comprising: receiving, by circuitry, a first entitlement message, which is a security message transmitted periodically, wherein the first entitlement message comprises entitlement data comprising an expiry time, access data enabling access to protected media content until the expiry time and an indicator data; determining, by the circuitry, whether an entitlement message is a first received entitlement message by verifying if entitlement data has already been stored, and in response to a positive determination storing, by the circuitry, entitlement data and the indicator data of the first entitlement message into a memory; receiving, by the circuitry, access information comprising a current time and a descrambling key; comparing, by the circuitry, the current time with the expiry time and decrypt the descrambling key with a decryption key of the access data, and grant access to the protected content in response of a positive comparison; receiving, by the circuitry, a subsequent entitlement message; updating, by the circuitry, the expiry time stored in the memory with the expiry time included in the subsequent entitlement messages if the subsequent entitlement message indicator data of the subsequent entitlement message is at least the same of the stored indicator data; and rejecting, by the circuitry, the subsequent entitlement message otherwise. ### Claim 10 (depends on 9) The access control method according to claim 9, wherein the entitlement data includes an identifier specific to the expiry time. ### Claim 11 (depends on 10) The access control method according to claim 10, further comprising: storing verification data enabling data enabling verification of the identifier in a one-time programmable memory; prior to using entitlement data to access media content, determining if the identifier of the entitlement data matches the verification data; and preventing use of the entitlement data to access media content if the identifier of the entitlement data does not match the verification data. ### Claim 12 (depends on 11) The access control method according to claim 11, further comprising: irreversibly physically altering the one-time programmable memory when storing data in the one-time programmable memory. ### Claim 13 (depends on 9) The access control method according to claim 9, further comprising storing the entitlement data in volatile memory. ### Claim 14 (depends on 9) The access control method according to claim 9, further comprising: storing the entitlement data in a one-time programmable memory; and preventing use of entitlement data comprising indicator data not stored in the one-time programmable memory. ### Claim 15 (depends on 9) The access control method according to claim 9, further comprising: determining, at the time of receiving the entitlement data, if the received entitlement data was received after previous entitlement data comprising indicator data has been stored in the access control module; and preventing storing of or to delete the entitlement data in response to the determination if the determination is affirmative.