# US 11,444,753 B1 · Protocol key negotiation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,444,753 B1 - Document ID: US11444753B1 - Status: Granted - Kind: B1 - Application number: 17/690,202 - Filed: 2022-03-09 - Published: 2022-09-15 - Granted: 2022-09-13 - Earliest claimed: 2021-03-09 - Assignees: ISARA Corporation - Applicants: ISARA Corporation - Inventors: Robert Williams; Alexander Truskovsky - Web page: https://patentgrep.com/patent/US11444753B1 ## CPC - H04L 9/0822: {using key encryption key} - H04L 9/0825: {using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates} - H04L 9/0852: {Quantum cryptography (transmission systems employing electromagnetic waves other than radio waves, e.g. light, infrared H04B10/00; wavelength-division multiplex systems H04J14/02; WDM arrangements H04J14/03)} - H04L 9/14: using a plurality of keys or algorithms - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In some aspects, a cryptography method includes executing, by operation of a first computing device associated with a first entity, a first handshake process with a second entity according to a first handshake protocol to establish a first symmetric encryption key for a first encryption protocol; executing, by operation of the first computing device, a second handshake process with the second entity to establish a second symmetric encryption key for a second encryption protocol. Executing the second handshake process includes: generating second handshake data according to a second handshake protocol; encrypting the second handshake data using the first symmetric encryption key with the first encryption protocol; and sending the encrypted second handshake data to a second computing device associated with the second entity; and using the second symmetric encryption key and the second encryption protocol for single-encrypted communication over a communication channel between the first and second entities. ## Claims ### Claim 1 A cryptography method for encrypted communication between a first entity and a second entity, the method comprising: by operation of a first computing device associated with the first entity, executing a first handshake process with the second entity according to a first handshake protocol, wherein the first handshake process establishes a first symmetric encryption key for a first encryption protocol; by operation of the first computing device associated with the first entity, executing a second handshake process with the second entity to establish a second symmetric encryption key for a second encryption protocol, wherein executing the second handshake process comprises: generating second handshake data according to a second handshake protocol; encrypting the second handshake data using the first symmetric encryption key with the first encryption protocol; and sending the encrypted second handshake data to a second computing device associated with the second entity; and using the second symmetric encryption key and the second encryption protocol for single-encrypted communication over a communication channel between the first and second entities. ### Claim 2 (depends on 1) The method of claim 1, wherein the first handshake protocol is a quantum-safe handshake protocol. ### Claim 3 (depends on 2) The method of claim 2, wherein the second handshake protocol is a quantum-vulnerable handshake protocol, and the first encryption protocol that is used to encrypt the second handshake data is a quantum-safe encryption protocol. ### Claim 4 (depends on 1) The method of claim 1, wherein the first and second encryption protocols are quantum-safe symmetric key encryption protocols. ### Claim 5 (depends on 1) The method of claim 1, wherein each of the first and second symmetric encryption keys have a length of 256 bits. ### Claim 6 (depends on 1) The method of claim 1, comprising, after completing the second handshake process, terminating use of the first encryption protocol for bulk communication between the first and second entities. ### Claim 7 A computing system comprising a first computing device associated with a first entity, the first computing device comprising: one or more processors; and memory storing instructions that are operable when executed by the one or more processors to perform one or more operations comprising: executing a first handshake process with the second entity according to a first handshake protocol, wherein the first handshake process establishes a first symmetric encryption key for a first encryption protocol; executing a second handshake process with the second entity to establish a second symmetric encryption key for a second encryption protocol, wherein executing the second handshake process comprises: generating second handshake data according to a second handshake protocol; encrypting the second handshake data using the first symmetric encryption key with the first encryption protocol; and sending the encrypted second handshake data to a second computing device associated with the second entity; and using the second symmetric encryption key and the second encryption protocol for single-encrypted communication over a communication channel between the first and second entities. ### Claim 8 (depends on 7) The computing system of claim 7, wherein the first handshake protocol is a quantum-safe handshake protocol. ### Claim 9 (depends on 8) The computing system of claim 8, wherein the second handshake protocol is a quantum-vulnerable handshake protocol, and the first encryption protocol that is used to encrypt the second handshake data is a quantum-safe encryption protocol. ### Claim 10 (depends on 7) The computing system of claim 7, wherein the first and second encryption protocols are quantum-safe symmetric key encryption protocols. ### Claim 11 (depends on 7) The computing system of claim 7, wherein each of the first and second symmetric encryption keys have a length of 256 bits. ### Claim 12 (depends on 7) The computing system of claim 7, wherein the operations further comprise after completing the second handshake process, terminating use of the first encryption protocol for bulk communication between the first and second entities. ### Claim 13 (depends on 7) The computing system of claim 7, comprising the second computing device. ### Claim 14 A non-transitory computer-readable medium storing instructions that are operable when executed by data processing apparatus associated with a first entity to perform operations comprising: executing a first handshake process with a second entity according to a first handshake protocol, wherein the first handshake process establishes a first symmetric encryption key for a first encryption protocol; executing a second handshake process with the second entity to establish a second symmetric encryption key for a second encryption protocol, wherein executing the second handshake process comprises: generating second handshake data according to a second handshake protocol; encrypting the second handshake data using the first symmetric encryption key with the first encryption protocol; and sending the encrypted second handshake data to a computing device associated with the second entity; and using the second symmetric encryption key and the second encryption protocol for single-encrypted communication over a communication channel between the first and second entities. ### Claim 15 (depends on 13) The non-transitory computer-readable medium of claim 13, wherein the first handshake protocol is a quantum-safe handshake protocol. ### Claim 16 (depends on 14) The non-transitory computer-readable medium of claim 14, wherein the second handshake protocol is a quantum-vulnerable handshake protocol, and the first encryption protocol that is used to encrypt the second handshake data is a quantum-safe encryption protocol. ### Claim 17 (depends on 13) The non-transitory computer-readable medium of claim 13, wherein the first and second encryption protocols are quantum-safe symmetric key encryption protocols. ### Claim 18 (depends on 13) The non-transitory computer-readable medium of claim 13, wherein each of the first and second symmetric encryption keys have a length of 256 bits. ### Claim 19 (depends on 13) The non-transitory computer-readable medium of claim 13, wherein the operations further comprise after completing the second handshake process, terminating use of the first encryption protocol for bulk communication between the first and second entities.