# US 8,782,803 B2 · System and method of encrypting a derivative work using a cipher created from its source > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,782,803 B2 - Document ID: US8782803B2 - Status: Granted - Kind: B2 - Application number: 12/760,091 - Filed: 2010-04-14 - Published: 2011-10-20 - Granted: 2014-07-15 - Earliest claimed: 2010-04-14 - Assignees: Legitmix, Inc. - Applicants: Omid Allen McDonald; David Ross McDonald - Inventors: Omid Allen McDonald; David Ross McDonald - Web page: https://patentgrep.com/patent/US8782803B2 ## CPC - G06F 21/10: Protecting distributed programs or content, e.g. vending or licensing of copyrighted material (protection in video systems or pay television H04N7/16) {; Digital rights management [DRM]} - G06Q 30/00: Commerce - H04L 9/0861: {Generation of secret information including derivation or calculation of cryptographic keys or passwords} - G11B 20/00086: {Circuits for prevention of unauthorised reproduction or copying, e.g. piracy (indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00)} - H04L 9/0866: {involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics} - H04L 2209/56: Financial cryptography, e.g. electronic payment or e-cash - H04L 2209/60: Digital content management, e.g. content distribution - Y10S 705/901: Digital rights management - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A derivative work is encrypted using a cipher created from digital sources used to create the derivative work. A software application made available for download permits a mix artist to generate a derivative-encrypted work from a derivative work that the mix artist has created using one or more of the digital sources. The derivative-encrypted work is streamed to a worldwide web server, where it is made available for download by consumers for a fee. The software application is also available for download by the consumers and permits the consumers to purchase and download any available derivative-encrypted work. However, the derivative-encrypted works can only be decrypted if the consumer has possession of a digital source for each of the source art works associated with the digital sources used to create the derivative work. ## Claims ### Claim 1 A method of encrypting a derivative work using a cipher created from digital sources used to create the derivative work in order to ensure a legal distribution of the derivative work through public channels, comprising: obtaining machine-readable input from a creator of the derivative work that provides an identification of each digital source used to create the derivative work; extracting source data from each of the digital sources used to create the derivative work; locating a source data sequence for each of the extracted source data that is unique within a predetermined range of each of the extracted source data; saving the source data sequence for each of the extracted source data as a marker in a header section created for a derivative-encrypted work; selecting a portion of the source data following the source data sequence for each of the extracted source data; creating the respective encryption keys by processing the selected portion for each of the extracted source data; combining the respective encryption keys to create the cipher; encrypting the derivative work using the cipher to create the derivative-encrypted work; storing the derivative-encrypted work on a public server; and making the derivative-encrypted work available on the public server. ### Claim 2 (depends on 1) The method as claimed in claim 1 further comprising encoding the marker using an encoding algorithm prior to saving the marker in the header section of the derivative-encrypted work. ### Claim 3 (depends on 1) The method as claimed in claim 1 wherein creating the respective encryption keys using the selected portion for each of the extracted source data comprises: rounding data values in the selected portion for each of the extracted source data to preserve only higher order bits of each data value. ### Claim 4 (depends on 1) The method as claimed in claim 1 wherein combining the respective encryption keys to create the cipher comprises using the key as the cipher if only one digital source was used to create the derivative work. ### Claim 5 (depends on 1) The method as claimed in claim 1 wherein combining the respective encryption keys to create the cipher comprises EXCLUSIVE ORing (XORing) the respective values together to create the cipher. ### Claim 6 (depends on 1) The method as claimed in claim 1 wherein combining the respective encryption keys to create the cipher comprises adding the values together to create the cipher. ### Claim 7 (depends on 1) The method as claimed in claim 1 wherein encrypting the derivative work using the cipher to create a derivative-encrypted work comprises: dividing the derivative work into cipher-sized portions; and sequentially EXCLUSIVE ORing (XORing) the cipher with the respective cipher-sized portions until the entire derivative work is encrypted. ### Claim 8 (depends on 1) The method as claimed in claim 1 wherein encrypting the derivative work using the cipher to create a derivative-encrypted work comprises: dividing the source data from the derivative work into cipher-sized portions; sequentially adding the values in the cipher to the respective values in the cipher-sized portions of source data until the entire derivative work is encrypted. ### Claim 9 A system for ensuring a legal distribution of a derivative work through public channels, comprising: a derivative work service server having a non-volatile memory, the derivative work service server being connected to a public network in such a way that it can be accessed by mix artists and consumers; and a software application stored on the non-volatile memory and available for download by the mix artists and the consumers, the software application comprising machine-executable code that permits the mix artists to upload derivative-encrypted works, which are derivative works encrypted using an encryption cipher created by processing source data extracted from respective digital sources used to create the derivative work, wherein the machine-executable code comprises program instructions that permit the mix artist to input to the machine-executable code an identity of each source art work used to create one of the derivative works and, if required, an identity of a digital source associated with each of the source art works, program instructions that open a copy of each digital source and extract source data there from, program instructions that locate a start point used to generate an encryption key from the source data of each digital source, program instructions that create the encryption key from the source data extracted from each digital source, program instructions for combining the encryption keys to create an encryption cipher; and program instructions for encrypting the derivative work and uploading the derivative-encrypted work to the derivative work service server, and the software application further comprising machine-executable code that permits the consumers to purchase derivative-encrypted works and download the derivative-encrypted works, and decrypt the derivative-encrypted work provided that the consumers are respectively in possession of a digital source for each source art work associated with respective digital sources used by the respective mix artists to create the respective derivative-encrypted works purchased by the respective consumers, so that the respective derivative-encrypted works can be decrypted using a decryption cipher created by processing source data extracted from the respective digital sources possessed by the consumer to create a respective decryption key from each of the digital sources possessed by the consumer, and combining the respective decryption keys to create the decryption cipher. ### Claim 10 (depends on 9) The system as claimed in claim 9 wherein the machine-executable code further comprises: program instructions that permit the consumer to browse the derivative-encrypted works available on the derivative work service server; and program instructions that permit the consumer to purchase one of the derivative, encrypted works available on the derivative work service server. ### Claim 11 (depends on 10) The system as claimed in claim 10 wherein the machine-executable code further comprises: program instructions that determine if the consumer possesses a digital source for each source art work used to create a derivative work encrypted in a derivative-encrypted work purchased by the consumer; program instructions that extract source data from each digital source; program instructions that locate a start point used to generate a decryption key from the source data of each digital source; program instructions that process the source data of each digital source to generate the decryption key; program instructions that combine the decryption keys to create a decryption cipher; and program instructions that decrypt and download the derivative-encrypted work to the consumer system to permit the consumer to render the derivative work. ### Claim 12 (depends on 11) The system as claimed in claim 11 wherein the machine-executable code further comprises program instructions that use an information push mechanism to display an option to purchase a digital source that is not possessed by the consumer. ### Claim 13 (depends on 9) The system as claimed in claim 9 further comprising program instructions that extract error correcting codes from a header section of the derivative-encrypted file in order to ensure that the decryption key(s) are identical to the encryption key(s) used to encrypt an encrypted mix in the derivative-encrypted work. ### Claim 14 A method of decrypting a derivative-encrypted work acquired by a consumer comprising: downloading by the consumer the derivative-encrypted work from a public server; extracting header information from a header section of the derivative encrypted work; obtaining from the header information source art work identifiers that indicate digital sources required to decrypt the derivative-encrypted work; locating each of the digital sources on the consumer system; extracting source data from each of the respective digital sources; obtaining from the header information a marker for the respective digital sources that identifies respective starting points used in the extracted source data to generate respective decryption keys; obtaining respective decryption key lengths from the header information; selecting a portion of the extracted source data extracted from each digital source using the respective markers and decryption key lengths to create a respective decryption key associated with each digital source; creating the respective decryption keys by processing the selected portions of source data; combining the respective decryption keys to create a decryption cipher; and decrypting the derivative-encrypted work using the decryption cipher to create a consumer mix. ### Claim 15 (depends on 14) The method as claimed in claim 14 wherein obtaining from the markers for the respective digital sources further comprises decoding the respective markers using a predetermined decoding algorithm. ### Claim 16 (depends on 14) The method as claimed in claim 14 further comprising storing the consumer mix on non-volatile memory of the consumer system. ### Claim 17 (depends on 14) The method as claimed in claim 14 wherein locating each of the digital sources on the consumer system further comprises prompting the consumer for digital source location information if any one of the digital sources cannot be located on the consumer system. ### Claim 18 (depends on 17) The method as claimed in claim 17 wherein if one or more of the digital sources are not available from non-volatile memory of the consumer system, the method further comprises displaying a warning message and further displaying an option to purchase the one or more missing digital sources.