# US 2016/0366115 A1 · Call encryption systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0366115 A1 - Document ID: US20160366115A1 - Status: Published application - Kind: A1 - Application number: 14/734,939 - Filed: 2015-06-09 - Published: 2016-12-15 - Earliest claimed: 2015-06-09 - Assignees: Verizon Patent and Licensing Inc. - Applicants: Verizon Patent and Licensing Inc. - Inventors: Mohammad Raheel Khalid; Manuel Enrique Caceres; Mauricio Pati Caldeira de Andrada; Paul Berman - Web page: https://patentgrep.com/patent/US20160366115A1 ## CPC - H04L 9/0819: {Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) (network architectures or network communication protocols for key distribution in a packet data network H04L63/062)} - H04L 9/0816: {Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use} - H04L 9/0841: {involving Diffie-Hellman or related key agreement protocols} - H04L 63/0471: {applying encryption by an intermediary, e.g. receiving clear information at the intermediary and encrypting the received information at the intermediary before forwarding} - H04L 63/0492: {by using a location-limited connection, e.g. near-field communication or limited proximity of entities} - H04M 3/2281: {Call monitoring, e.g. for law enforcement purposes; Call tracing; Detection or prevention of malicious calls} - H04W 12/033: of the user plane, e.g. user's traffic - H04W 12/041: Key generation or derivation - H04W 12/0471: Key exchange - G06F 2221/2133: Verifying human interaction, e.g., Captcha - H04L 2209/80: Wireless - H04W 12/33: using wearable devices, e.g. using a smartwatch or smart-glasses - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Techniques described herein may be used to encrypt a telephone call between users. User devices (e.g., smart phones) may be connected to encryption relay devices that operate as relays between headsets worn by the user and the user devices. As information passes from the headset toward a corresponding user device, an encryption relay device may encrypt the information before the information reaches the user device so that the user device transmits encrypted call information to the other user participating in the call. When encrypted information is received, and travels from the user device to the headset, the encryption relay device may decrypt the information before it reaches the headset. Thus, the techniques described herein provide an end-to-end encryption solution to telephone calls. ## Claims ### Claim 1 A method performed by an encryption relay device, comprising: detecting, by the an encryption relay device, a call between a user device, connected to the encryption relay device, and another user device, which is connected to a second encryption relay device; inserting, by the encryption relay device, audio signals within the call, the audio signals encoding information used to perform a key exchange with the second encryption relay device to exchange one or more encryption keys for the call receiving, by the encryption relay device and from the user device, encrypted call information corresponding to the call; decrypting, by the encryption relay device, the encrypted call information based on the one or more encryption keys, to obtain a decrypted version of call audio; receiving, by the encryption relay device, call information originating from a user of the user device; encrypting, by the encryption relay, the call information originating from the user, based on the one or more encryption keys; and communicating, by the encryption relay device, the encrypted call information, originating from the user, to the user device to relay the encrypted call information, originating from the user, as part of the call. ### Claim 2 (depends on 1) The method of claim 1, wherein: the encryption relay device is connected to the user device via a first short-range wireless interface, and the encryption relay device is connected to a headset device via a second short-range wireless interface. ### Claim 3 (depends on 1) The method of claim 1, further comprising: storing the one or more encryption keys; and deleting the one or more encryption keys in response to a command from the user to clear a memory of the computing device. ### Claim 4 (depends on 1) The method of claim 1, further comprising: generating an encryption key for encrypting and decrypting call information based on a physical arrangement of manually programmable features of the encryption relay device. ### Claim 5 (depends on 1) The method of claim 1, further comprising: receiving call information, originating from the other user device, that includes a timestamp; determining a duration of time defined by a difference between the timestamp and a current time; and determining whether a third-party device is participating in the call based on the duration of time. ### Claim 6 (depends on 1) The method of claim 1, further comprising: receiving an audio signal originating from the second encryption relay device; detecting an identity certificate embedded in the audio signal; and authenticating the second encryption relay device based on a comparison of information included in the identity certificate with a manufacturer public key stored locally by the encryption relay device. ### Claim 7 (depends on 1) The method of claim 1, further comprising: performing a Diffie Hellman procedure to determine a symmetric encryption key between the encryption relay device and the second encryption relay device. ### Claim 8 (depends on 1) The method of claim 1, further comprising: clearing a memory of the encryption relay device based on an input from the user; creating an encryption key based on a dial code physically programmed into the encryption relay device by the user; using the encryption key to perform an audio CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) procedure to verify whether a third party device is participating in the call. ### Claim 9 (depends on 1) The method of claim 1, wherein the audio signals within the call are ultrasonic audio signals. ### Claim 10 An encryption relay device comprising circuitry to: detect a call between a user device, connected to the encryption relay device, and another user device, which is connected to a second encryption relay device; insert audio signals within the call, the audio signals encoding information used to perform a key exchange with the second encryption relay device to exchange one or more encryption keys for the call receive, from the user device, encrypted call information corresponding to the call; decrypt the encrypted call information based on the one or more encryption keys, to obtain a decrypted version of call audio; receive call information originating from a user of the user device; encrypt the call information originating from the user, based on the one or more encryption keys; and communicate the encrypted call information, originating from the user, to the user device to relay the encrypted call information, originating from the user, as part of the call. ### Claim 11 (depends on 10) The computing device of claim 10, wherein: the encryption relay device is connected to the user device via a first short-range wireless interface, and the encryption relay device is connected to a headset device via a second short-range wireless interface. ### Claim 12 (depends on 10) The computing device of claim 10, wherein the circuitry further to: storing the one or more encryption keys; and deleting the one or more encryption keys in response to a command from the user to clear a memory of the computing device. ### Claim 13 (depends on 10) The computing device of claim 10, wherein the circuitry further to: generate an encryption key for encrypting and decrypting call information based on a physical arrangement of manually programmable features of the encryption relay device. ### Claim 14 (depends on 10) The computing device of claim 10, wherein the circuitry further to: receive call information, originating from the other user device, that includes a timestamp; determine a duration of time defined by a difference between the timestamp and a current time; and determine whether a third-party device is participating in the call based on the duration of time. ### Claim 15 (depends on 10) The computing device of claim 10, wherein the circuitry further to: receive an audio signal originating from the second encryption relay device; detect an identity certificate embedded in the audio signal; and authenticate the second encryption relay device based on a comparison of information included in the identity certificate with a manufacturer public key stored locally by the encryption relay device. ### Claim 16 (depends on 10) The computing device of claim 10, wherein the circuitry further to: performing a Diffie Hellman procedure to determine a symmetric encryption key between the encryption relay device and the second encryption relay device. ### Claim 17 (depends on 10) The computing device of claim 10, wherein the circuitry further to: clear a memory of the encryption relay device based on an input from the user; create an encryption key based on a dial code physically programmed into the encryption relay device by the user; use the encryption key to perform an audio CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) procedure to verify whether a third party device is participating in the call. ### Claim 18 A computing device comprising circuitry to: detect, via a first interface, a call involving the computing device; insert, via the first interface, audio signals within the call, the audio signals encoding information used to perform a key exchange, to exchange one or more encryption keys for the call; receive, via the first interface, encrypted call information corresponding to the call; decrypt, via an encryption module, the encrypted call information based on the one or more encryption keys, to obtain a decrypted version of call audio; receive, via a second interface, call information originating from a user; encrypt, via the encryption module, the call information originating from the user, based on the one or more encryption keys; and communicate, via the first information, the encrypted call information, originating from the user, as part of the call ### Claim 19 (depends on 18) The computing device of claim 18, wherein: the first interface is connected to a user device, involved in the call, via a first short-range wireless interface, and the second interface is connected to a headset device via a second short-range wireless interface. ### Claim 20 (depends on 18) The computing device of claim 18, comprising circuitry further to: clear a memory of the computing device based on an input from the user; create an encryption key based on a dial code physically programmed into the computing device by the user; and use the encryption key to perform an audio CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) procedure to verify whether a third party device is participating in the call.