# US 10,873,773 B2 · Countermeasure for cryptographic cribs > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,773 B2 - Document ID: US10873773B2 - Status: Granted - Kind: B2 - Application number: 16/039,749 - Filed: 2018-07-19 - Published: 2020-01-23 - Granted: 2020-12-22 - Earliest claimed: 2018-07-19 - Assignees: Cox Communications, Inc. - Applicants: Cox Communications, Inc. - Inventors: Kinney C. Bacon - Web page: https://patentgrep.com/patent/US10873773B2 ## CPC - H04N 21/2347: involving video stream encryption - H04L 9/0631: {Substitution permutation network [SPN], i.e. cipher composed of a number of stages or rounds each involving linear and nonlinear transformations, e.g. AES algorithms} - H04L 9/14: using a plurality of keys or algorithms - H04L 63/0428: {wherein the data content is protected, e.g. by encrypting or encapsulating the payload} - H04N 21/2541: {Rights Management (protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08)} - H04N 21/26613: {for generating or managing keys in general (key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04)} - H04L 2209/60: Digital content management, e.g. content distribution - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Systems, methods and computer readable media for providing users with encrypted content data associated with a service are disclosed. A device may receive first content data. The device may encrypt the first content data using a first key to obtain first encrypted data. The device may generate second encrypted data by applying a cipher substitution to the first encrypted data using a second key. The device may cause to send the second encrypted data to a second device. ## Claims ### Claim 1 A device comprising: at least one computer processor; and at least one non-transitory storage medium storing computer-executable code comprising: receiving first content data; encrypting the first content data using a first key to obtain first encrypted data; generating second encrypted data by applying a cipher substitution to the first encrypted data using a second key; generating third encrypted data by applying a second cipher substitution to the second encrypted data using a third key, wherein the second cipher substitution is different from the first cipher substitution; and causing to send the third encrypted data to a second device. ### Claim 2 (depends on 1) The device of claim 1, wherein the first key is one of a private key or a public key of a key pair. ### Claim 3 (depends on 1) The device of claim 1, wherein the generating the second encrypted data comprises: determining a first cipher algorithm from a plurality of cipher algorithms based on an index value; and determining the second key based on the first cipher algorithm. ### Claim 4 (depends on 3) The device of claim 3, wherein the computer-executable code further comprises: causing to send the index value to the second device. ### Claim 5 (depends on 1) The device of claim 1, wherein the cipher substitution includes one or more of: a simple substitution, a polyalphabetic substitution, or a polygraphic substitution. ### Claim 6 (depends on 1) The device of claim 1, wherein the computer-executable code further comprises: causing to send a value indicative of the second key to the second device. ### Claim 7 A system, comprising: at least one computer processor; and at least one non-transitory storage medium storing computer-executable code comprising: receiving first content data; encrypting the first content data using a first key to obtain first encrypted data; generating second encrypted data by applying a cipher substitution to the first encrypted data using a second key; generating third encrypted data by applying a second cipher substitution to the second encrypted data using a third key, wherein the second cipher substitution is different from the first cipher substitution; and causing to send the third encrypted data to a second device. ### Claim 8 (depends on 7) The system of claim 7, wherein the computer-executable code further comprises: storing a plurality of pseudorandom algorithms; and determining the cipher substitution from the plurality of pseudorandom algorithms based on a first index value. ### Claim 9 (depends on 7) The system of claim 7, wherein the computer-executable code further comprises receiving a first index value prior to the first encrypted data. ### Claim 10 (depends on 7) The system of claim 7, wherein the computer-executable code further comprises: receiving third encrypted data; and decrypting the third encrypted data using the second key to obtain a first index value. ### Claim 11 (depends on 7) The system of claim 7, wherein the computer-executable code further comprises: causing the content data to be displayed on a display of the second device. ### Claim 12 (depends on 7) The system of claim 7, wherein the first encrypted data is encrypted according to transport layer security (TLS) or secure socket layer (SSL). ### Claim 13 A method comprising: receiving, by one or more processors, first content data; encrypting, by the one or more processors, the first content data using a first key to obtain first encrypted data; generating, by the one or more processors, second encrypted data by applying a cipher substitution to the first encrypted data using a second key; and generating, by the one or more processors, third encrypted data by applying a second cipher substitution to the second encrypted data using a third key, wherein the second cipher substitution is different from the first cipher substitution; and causing to send, by the one or more processors, the third encrypted data to a second device. ### Claim 14 (depends on 13) The method of claim 13, wherein the first key is one of a private key or a public key of a key pair. ### Claim 15 (depends on 13) The method of claim 13, wherein the generating the second encrypted data comprises: determining, by the one or more processors, a first cipher algorithm from a plurality of cipher algorithms based on an index value; and determining, by the one or more processors, the second key based on the first cipher algorithm. ### Claim 16 (depends on 15) The method of claim 15, further comprising: causing to send, by the one or more processors, the index value to the second device. ### Claim 17 (depends on 13) The method of claim 13, wherein the cipher substitution includes one or more of: a simple substitution, a polyalphabetic substitution, or a polygraphic substitution. ### Claim 18 (depends on 13) The method of claim 13, further comprising causing to send, by the one or more processors, a value indicative of the second key to the second device.