# US 2022/0286299 A1 · Decentralized, dynamic media key block for broadcast encryption > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0286299 A1 - Document ID: US20220286299A1 - Status: Published application - Kind: A1 - Application number: 17/189,757 - Filed: 2021-03-02 - Published: 2022-09-08 - Earliest claimed: 2021-03-02 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Yacov Manevich; Dulce B. Ponceleon; Petr Novotny; Nitin Gaur - Web page: https://patentgrep.com/patent/US20220286299A1 ## CPC - G06F 21/602: {Providing cryptographic facilities or services} - H04L 9/3255: {using group based signatures, e.g. ring or threshold signatures} - G06F 21/64: Protecting data integrity, e.g. using checksums, certificates or signatures - H04L 9/0637: {Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM]} - H04L 9/0836: {using tree structure or hierarchical structure} - H04L 9/0891: {Revocation or update of secret information, e.g. encryption key update or rekeying} - H04L 9/3239: {involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD} - H04L 9/50: {using hash chains, e.g. blockchains or hash trees} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A processor may segment a media key block into two or more subsets. Each of the two or more subsets may be respectively associated with a particular group of receivers, and each receiver of the particular group of receivers may be in a blockchain network. The processor may receive, from a first receiver, a request for permission to process the media key block. The processor may identify which of the two or more subsets that the first receiver is associated. The processor may provide a media key block value to the first receiver. ## Claims ### Claim 1 A method for a dynamic media key block, the method comprising: segmenting a media key block into two or more subsets, wherein each of the two or more subsets are respectively associated with a particular group of receivers, and wherein each receiver of the particular group of receivers is in a blockchain network; receiving, from a first receiver, a request for permission to process the media key block; identifying which of the two or more subsets that the first receiver is associated; and providing a media key block value to the first receiver. ### Claim 2 (depends on 1) The method of claim 1, wherein the media key block is associated with a content, wherein the content is encrypted using a content key, wherein the content key is encrypted using one or more subset difference keys associated with the two or more subsets ### Claim 3 (depends on 1) The method of claim 1, wherein each of the two or more subsets are further associated with respective particular media key block values, and wherein the media key block value provided to the first receiver is associated with a first subset. ### Claim 4 (depends on 1) The method of claim 1, wherein identifying which of the two or more subsets that the first receiver is associated includes identifying a unique identification value associated with the first receiver, wherein the unique identification value indicates a placement of the first receiver in the two or more subsets. ### Claim 5 (depends on 1) The method of claim 1, wherein the media key block is segmented into the two or more subsets based on content access. ### Claim 6 (depends on 5) The method of claim 5, further comprising: providing one or more updates to the particular group of receivers based on which of the two or more subsets the particular group of receivers are associated. ### Claim 7 (depends on 5) The method of claim 5, further comprising: revoking access to a media based on the two or more subsets the particular group of receivers are associated. ### Claim 8 A system for a dynamic media key block, the system comprising: a memory; and a processor in communication with the memory, the processor being configured to perform operations comprising: segmenting a media key block into two or more subsets, wherein each of the two or more subsets are respectively associated with a particular group of receivers, and wherein each receiver of the particular group of receivers is in a blockchain network; receiving, from a first receiver, a request for permission to process the media key block; identifying which of the two or more subsets that the first receiver is associated; and providing a media key block value to the first receiver. ### Claim 9 (depends on 8) The system of claim 8, wherein the media key block is associated with a content, wherein the content is encrypted using a content key, wherein the content key is encrypted using one or more subset difference keys associated with the two or more subsets ### Claim 10 (depends on 8) The system of claim 8, wherein each of the two or more subsets are further associated with respective particular media key block values, and wherein the media key block value provided to the first receiver is associated with a first subset. ### Claim 11 (depends on 8) The system of claim 8, wherein identifying which of the two or more subsets that the first receiver is associated includes identifying a unique identification value associated with the first receiver, wherein the unique identification value indicates a placement of the first receiver in the two or more subsets. ### Claim 12 (depends on 8) The system of claim 8, wherein the media key block is segmented into the two or more subsets based on content access. ### Claim 13 (depends on 12) The system of claim 12, wherein the operations further comprise: providing one or more updates to the particular group of receivers based on which of the two or more subsets the particular group of receivers are associated. ### Claim 14 (depends on 12) The system of claim 12, wherein the operations further comprise: revoking access to a media based on the two or more subsets the particular group of receivers are associated. ### Claim 15 A computer program product for a dynamic media key block, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processors to perform a function, the function comprising: segmenting a media key block into two or more subsets, wherein each of the two or more subsets are respectively associated with a particular group of receivers, and wherein each receiver of the particular group of receivers is in a blockchain network; receiving, from a first receiver, a request for permission to process the media key block; identifying which of the two or more subsets that the first receiver is associated; and providing a media key block value to the first receiver. ### Claim 16 (depends on 15) The computer program product of claim 15, wherein the media key block is associated with a content, wherein the content is encrypted using a content key, wherein the content key is encrypted using one or more subset difference keys associated with the two or more subsets ### Claim 17 (depends on 15) The computer program product of claim 15, wherein each of the two or more subsets are further associated with respective particular media key block values, and wherein the media key block value provided to the first receiver is associated with a first subset. ### Claim 18 (depends on 15) The computer program product of claim 15, wherein identifying which of the two or more subsets that the first receiver is associated includes identifying a unique identification value associated with the first receiver, wherein the unique identification value indicates a placement of the first receiver in the two or more subsets. ### Claim 19 (depends on 15) The computer program product of claim 15, wherein the media key block is segmented into the two or more subsets based on content access. ### Claim 20 (depends on 19) The computer program product of claim 19, wherein the function further comprises: providing one or more updates to the particular group of receivers based on which of the two or more subsets the particular group of receivers are associated.