# US 7,613,182 B2 · Distributed and secured method and system for protecting and distributing audiovisual flows > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,613,182 B2 - Document ID: US7613182B2 - Status: Granted - Kind: B2 - Application number: 11/344,897 - Filed: 2006-02-01 - Published: 2007-08-16 - Granted: 2009-11-03 - Earliest claimed: 2003-08-11 - Inventors: Daniel Lecomte; Reda Hosny; Mohammed Lamtouni - Web page: https://patentgrep.com/patent/US7613182B2 ## CPC - 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 7/17318: {Direct or substantially direct transmission and handling of requests} - H04N 21/234327: {by decomposing into layers, e.g. base layer and one or more enhancement layers} - H04N 21/2347: involving video stream encryption - 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 21/2665: Gathering content from different sources, e.g. Internet and satellite - H04N 21/631: {Multimode Transmission, e.g. transmitting basic layers and enhancement layers of the content over different transmission paths or transmitting with different error corrections, different keys or with different transmission protocols} - 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 process for secure distribution of digital audiovisual streams according to a standard, normalized or proprietary format, on which streams a separation of the stream into two parts is made prior to transmission to equipment of an addressee to generate a modified main stream having a format of the original stream and complementary information of any format including digital information suitable to permit reconstruction of the original stream, wherein a transmission is made, by separate paths during distribution of the modified main stream from a distribution server and of the complementary information to the equipment of the addressee from a secure central server passing via at least one local server connecting the equipment of the addressee to the local server via at least one access point. ## Claims ### Claim 1 A process for distribution of digital audiovisual streams, comprising: processing an original audiovisual stream to generate a modified stream having a format corresponding to a format of the original stream and to generate complementary information of any format, the complementary information including digital information suitable to permit reconstruction of the original stream; transmitting to equipment of an addressee, using separate transmission paths, the modified stream from a distribution server and the complementary information from a secure central server, wherein the transmission path for the complementary information passes through at least one local server coupled to the equipment of the addressee via at least one access point, wherein the secure central server performs a segmentation of the complementary information with respective segments corresponding to audiovisual elements in units of streams of complementary information with a variable size, wherein, before sending the complementary information from the local server to the equipment of the addressee, the complementary information is decrypted with a first encryption key and re-encrypted with a second encryption key, wherein the second encryption key is constructed during an authentication stage between the equipment of the addressee and any local server. ### Claim 2 A process for distribution of digital audiovisual streams, comprising: processing at least one original digital audiovisual stream to generate a modified stream having a format corresponding to a format of the original stream and complementary information of any format, the complementary information including digital information suitable to permit reconstruction of the original stream; and transmitting to equipment of an addressee, using separate transmission paths, the modified stream from a distribution server and the complementary information from a secure central server, wherein the transmission path for the complementary information passes through at least one local server coupled to the equipment of the addressee via at least one access point; wherein transmitting the complementary information includes applying a mechanism for regulating the quantity of information distributed into a distributed network, taking account of capacities and restrictions of the distributed network in terms of storage and of access time. ### Claim 3 (depends on 2) The process of claim 2, wherein the secure central server performs a segmentation of the complementary information with respective segments corresponding to audiovisual elements in units of streams of complementary information with a variable size. ### Claim 4 (depends on 3) The process according to claim 3, wherein respective segments correspond to a subjectively coherent entire audiovisual element in units of streams of complementary information with a variable size. ### Claim 5 (depends on 3) The process according to claim 3, wherein units of streams of complementary information are organized in several layers corresponding to layers of scalability of the original audiovisual stream. ### Claim 6 (depends on 5) The process according to claim 5, wherein, prior to sending to a local server, the secure central server encrypts the units of the streams of complementary information with a first encryption key. ### Claim 7 (depends on 2) The process according to claim 2, further comprising, before sending the complementary information from the local server to the equipment of the addressee, decrypting the complementary information with a first encryption key and re-encrypting the complementary information with a second encryption key. ### Claim 8 (depends on 7) The process according to claim 7, wherein re-encrypting of the complementary information with the second key is adaptive as a function of the throughput capacities of the equipment of the addressee. ### Claim 9 (depends on 7) The process according to claim 7, further comprising the local server generating a session key associated with a session established with at least one client, with the host server becoming a host server of the session during the entire lifetime of the session key. ### Claim 10 (depends on 7) The process according to claim 7, wherein the second encryption key is valid solely during the time of a continuous session between the equipment of the addressee and at least one local server. ### Claim 11 (depends on 7) The process according to claim 7, further comprising generating an access ticket per session, containing information concerning the second encryption key, wherein the second encryption key is valid solely during the session and expires at the end of the validity of the access ticket. ### Claim 12 (depends on 2) The process according to claim 2, wherein transmitting the complementary information into the distributed network has the property of scalability in a rate at which the complementary information is transmitted into the distributed network. ### Claim 13 (depends on 2) The process of claim 2, wherein the at least one access point includes at least one access point for mobile addressee equipment. ### Claim 14 A system for distributing audiovisual streams, the system comprising: a device for separating an original audiovisual stream into a modified stream and into complementary information, wherein the modified stream has a format corresponding to a format of the original stream, and wherein the complementary information has any format and includes digital information suitable to permit reconstruction of the original stream, at least one multimedia server configured to contain protected audiovisual streams, and at least one secure central server configured to distribute the complementary information, wherein the secure central server is further adapted to perform a segmentation of the complementary information with respective segments corresponding to audiovisual elements in units of streams of complementary information with a variable size, wherein the secure central server includes an encryption module configured to encrypt the complementary information prior to transmitting the complementary information to a local server for transmission to equipment of an addressee, and wherein the encryption module is further configured to encrypt the complementary information using an encryption key determined by a title of the original stream corresponding to the complementary information and determined by the local server to which the complementary information is to be transmitted. ### Claim 15 A system for distributing audiovisual streams, the system comprising: a device for separating an original audiovisual stream into a modified stream and into complementary information, wherein the modified stream has a format corresponding to a format of the original stream, and wherein the complementary information has any format and includes digital information suitable to permit reconstruction of the original stream, at least one multimedia server configured to contain protected audiovisual streams, and at least one secure central server configured to distribute the complementary information, wherein the secure central server is further adapted to perform a segmentation of the complementary information with respective segments corresponding to audiovisual elements in units of streams of complementary information with a variable size, wherein the secure central server is further configured to regulate the quantity of information distributed into a distributed network, taking account of the capacities and restrictions of the distributed network in terms of storage and of access time. ### Claim 16 (depends on 15) The system of claim 15, wherein the secure central server comprises: an encryption module configured to encrypt the complementary information prior to transmitting the complementary information to a local server for transmission to equipment of an addressee. ### Claim 17 (depends on 15) The system according to claim 15, wherein the segments correspond, respectively, to subjectively coherent entire audiovisual elements in units of streams of complementary information with a variable size.