# US 2018/0324547 A1 · Systems and methods for high-assurance indoor proximity and location > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0324547 A1 - Document ID: US20180324547A1 - Status: Published application - Kind: A1 - Application number: 15/584,055 - Filed: 2017-05-02 - Published: 2018-11-08 - Earliest claimed: 2017-05-02 - Assignees: Fuji Xerox Co., Ltd. - Applicants: Fuji Xerox Co., Ltd. - Inventors: Jacob Biehl; Adam Joseph Lee; Gerald Filby - Web page: https://patentgrep.com/patent/US20180324547A1 ## CPC - H04W 4/023: {using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds} - H04L 9/3247: {involving digital signatures} - H04L 63/0823: {using certificates (cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263)} - H04W 4/33: for indoor environments, e.g. buildings - H04W 12/104: Location integrity, e.g. secure geotagging - H04W 12/61: Time-dependent - H04W 12/64: using geofenced areas - H04L 63/0442: {wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption (cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30)} - H04L 2209/80: Wireless - H04W 4/02: Services making use of location information - H04W 4/027: {using movement velocity, acceleration information} - H04W 4/029: Location-based management or tracking services - H04W 4/80: Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract This disclosure focuses on providing a technology framework for creating secure, location-based applications. The disclosure details a technology solution that can allow users to access secure information on commodity computation devices (e.g., tablets and smartphones) without a heavy infrastructure burden. The technology consists of a collection of software services that run on end-user devices, services on network accessible servers (e.g., cloud), and a specialized device that provides high-assurance location services atop a tamper resistant, trusted computation platform. ## Claims ### Claim 1 A computer-implemented method, the method being performed in a computerized system comprising a central processing unit, a localization signal receiver and a memory, the computer-implemented method comprising: a. receiving at least one localization signal using the localization signal receiver; b. measuring a strength of the received localization signal; c. determining whether the computerized system is co-located with an anchor device; and d. if the computerized system is determined to be co-located with the anchor device, determining a location based at least on the measured strength of the received localization signal. ### Claim 2 (depends on 1) The computer-implemented method of claim 1, wherein determining whether the computerized system is co-located with the anchor device comprises receiving a first message comprising a key from the anchor device; transmitting a second message comprising at least the received key back to the anchor device; and analyzing, at the anchor device, a timing of the first message in relation to a timing of the second message. ### Claim 3 (depends on 2) The computer-implemented method of claim 2, wherein the computerized system is determined to be co-located with the anchor device if a time lapsed between the first message and the second message does not exceed a predetermined threshold. ### Claim 4 (depends on 2) The computer-implemented method of claim 2, wherein the key is a randomly generated nonce. ### Claim 5 (depends on 2) The computer-implemented method of claim 2, wherein the second message is signed using a private cryptographic key associated with the computerized system and wherein the anchor device validates the second message using a public key associated with the computerized system. ### Claim 6 (depends on 2) The computer-implemented method of claim 2, wherein receiving the first message and transmitting the second message are performed via a near field communication (NFC) protocol. ### Claim 7 (depends on 2) The computer-implemented method of claim 2, wherein the second message further comprises the measured strength of the received localization signal. ### Claim 8 (depends on 2) The computer-implemented method of claim 2, wherein the anchor device transmits a third message to a server, the third message comprising at least the second message and a location proof of the anchor device. ### Claim 9 (depends on 8) The computer-implemented method of claim 8, wherein the third message is signed using a private cryptographic key associated with the anchor device and wherein the server validates the third message using a public key associated with the anchor device. ### Claim 10 (depends on 2) The computer-implemented method of claim 2, wherein the key is unique. ### Claim 11 (depends on 1) The computer-implemented method of claim 1, wherein the received localization signal is provided by a beacon disposed in a room of a building. ### Claim 12 (depends on 1) The computer-implemented method of claim 1, wherein the anchor device is a trusted device comprising a trusted execution environment. ### Claim 13 (depends on 1) The computer-implemented method of claim 1, wherein the determining a location based at least on the measured strength of the received localization signal is performed on a server and wherein the server is configured to transmit a location proof to the computerized system. ### Claim 14 (depends on 13) The computer-implemented method of claim 13, wherein the location proof is transmitted to the computerized system via the anchor device. ### Claim 15 (depends on 1) The computer-implemented method of claim 1, wherein the computerized system executes a user application and wherein the location proof is provided to the user application. ### Claim 16 (depends on 1) The computer-implemented method of claim 1, further comprising anchoring the anchor device. ### Claim 17 (depends on 16) The computer-implemented method of claim 16, wherein anchoring the anchor device comprises receiving, at the anchor device, at least one second localization signal; measuring a strength of the received second localization signal and determining a location of the anchor device based at least on the measured strength of the received localization signal. ### Claim 18 (depends on 17) The computer-implemented method of claim 17, wherein the determining a location of the anchor device based at least on the measured strength of the received second localization signal is performed on a server and wherein the server is configured to transmit a location proof to the anchor device. ### Claim 19 (depends on 18) The computer-implemented method of claim 18, further comprising detecting a motion of the anchor device and invalidating the location proof of the anchor device based on the detected motion. ### Claim 20 (depends on 19) The computer-implemented method of claim 19, wherein the anchor device comprises an accelerometer and wherein the motion of the anchor device is detected using the accelerometer. ### Claim 21 (depends on 19) The computer-implemented method of claim 19, wherein the location proof of the anchor device is invalidated when the detected motion exceeds a predetermined threshold. ### Claim 22 (depends on 1) The computer-implemented method of claim 1, wherein determining whether the computerized system is co-located with an anchor device is performed periodically. ### Claim 23 A non-transitory computer-readable medium embodying a set of computer-executable instructions, which, when executed in connection with a computerized system comprising a central processing unit, a localization signal receiver, a display and a memory, cause the computerized system to perform a method comprising: a. receiving at least one localization signal using the localization signal receiver; b. measuring a strength of the received localization signal; c. determining whether the computerized system is co-located with an anchor device; and d. if the computerized system is determined to be co-located with the anchor device, determining a location based at least on the measured strength of the received localization signal. ### Claim 24 A computerized system comprising a central processing unit, a localization signal receiver and a memory, the memory storing a set of computer-readable instructions causing the computerized system to perform a method comprising: a. receiving at least one localization signal using the localization signal receiver; b. measuring a strength of the received localization signal; c. determining whether the computerized system is co-located with an anchor device; and d. if the computerized system is determined to be co-located with the anchor device, determining a location based at least on the measured strength of the received localization signal.