Wireless Fine Time Measurement Authentication

Patent metadata

Field	Value
Publication number	US-2023055972-A1
Application number	US-202117406059-A
Country	US
Kind code	A1
Filing date	Aug 18, 2021
Priority date	Aug 18, 2021
Publication date	Feb 23, 2023
Grant date	—

Abstract

A Fine Time Measurement (FTM) authentication system and method include performing a FTM transaction comprising at least one FTM-ACK message pair transmitted and received via a first communication channel between two endpoints, where the at least one FTM-ACK message pair contains timestamp values of message departure time and message arrival time during the FTM transaction. At least one authenticating value indicative of timestamp values of the at least one FTM-ACK message pair arrival and departure times during the FTM transaction is then transmitted via a second communication channel. FTM timestamp values are recovered from the received at least one authenticating value, which are compared with the received FTM timestamp values. The received FTM timestamp values can be authenticated if there is a match between the recovered FTM timestamp values and the received FTM timestamp values.

First claim

What is claimed is:

1 . A Fine Time Measurement (FTM) authentication method, comprising:
receiving, via a first communication channel, a first FTM message including a departure timestamp of a previous FTM message and an arrival timestamp of a previous ACK message corresponding to the previous FTM message; sending, via the first communication channel, a corresponding first ACK message in response to receiving the first FTM message; receiving, via a second communication channel, an authenticating value indicative of the time of departure and arrival timestamp values of at least the first FTM message and at least the first corresponding ACK messages; and authenticating the first FTM and ACK time of departure and arrival timestamps in response to evaluating the authenticating value.

2 . The authentication method of claim 1 , wherein authenticating the first FTM and ACK time of departure and arrival timestamps further comprising:
recovering the departure and arrival timestamp values from the received authenticating value; comparing the recovered timestamp values with observed FTM-ACK time of departure and arrival timestamps; and authenticating the time of departure and arrival timestamps in response to a match between the compared timestamp values.

3 . The authentication method of claim 1 , wherein receiving an authenticating value via a second communication channel comprises receiving a hash value of the timestamp values via a secure side channel.

4 . The authentication method of claim 1 , wherein receiving an authenticating value via a second communication channel comprises receiving an authenticating value after transmission of each ACK message in response to receiving an FTM message, the authenticating value indicative of timestamp values of the FTM and ACK message arrival and departure times.

5 . The authentication method of claim 1 , wherein receiving an authenticating value via a second communication channel comprises receiving an authenticating value after transmission of each ACK message in response to receiving an FTM message, the authenticating value indicative of a hash value of the FTM and ACK message arrival and departure timestamps.

6 . The authentication method of claim 5 , wherein authenticating the first FTM and ACK time of departure and arrival timestamps comprises:
determining the departure and arrival timestamp values from the received hash value; comparing the recovered timestamp values with observed FTM-ACK time of departure and arrival timestamps; and authenticating the time of departure and arrival timestamps in response to a match between the compared timestamp values.

7 . The authentication method of claim 1 , wherein receiving an authenticating value via a second communication channel comprises receiving the authenticating value at an FTM initiator.

8 . The authentication method of claim 1 , wherein receiving an authenticating value via a second communication channel comprises receiving the authenticating value at an FTM responder.

9 . A device for performing Fine Time Measurement (FTM) authentication, comprising:
a wireless receiver configured to receive, via a first communication channel, a first FTM message including a previous FTM message departure timestamp and a previous corresponding ACK message arrival timestamp; a wireless transmitter configured to transmit, via the first communication channel, a corresponding first ACK message in response to receiving the first FTM message; a receiver configured to receive, via a second communication channel, an authenticating value indicative of the time of departure and arrival timestamp values of at least the first FTM message and at least the first corresponding ACK messages; and logic configured to evaluate the authenticating value and authenticate the first FTM and ACK time of departure and arrival timestamps in response to evaluating the authenticating value.

10 . The device of claim 9 , wherein the logic is further configured to:
recover the departure and arrival timestamp values from the received authenticating value; compare the recovered timestamp values with observed FTM-ACK time of departure and arrival timestamps; and authenticate the time of departure and arrival timestamps in response to a match between the compared timestamp values.

11 . The device of claim 9 , wherein the receiver receiving the authenticating value via a second communication channel comprises the wireless receiver receiving a hash value of the timestamp values via a secure side channel.

12 . The device of claim 9 , wherein the receiver receiving the authenticating value via a second communication channel comprises the wireless receiver receiving an authenticating value after transmission of each FTM-ACK message pair indicative of timestamp values of the FTM and ACK message arrival and departure times.

13 . The device of claim 9 , wherein the receiver receiving the authenticating value via a second communication channel comprises the wireless receiver receiving the authenticating at an FTM responder.

14 . The device of claim 9 , wherein the receiver receiving the authenticating value via a second communication channel comprises the wireless receiver receiving the authenticating value at an FTM initiator.

15 . A non-downloadable computer-readable medium having encoded thereon a computer-executable method of detecting hacking of a Fine Time Measurement (FTM) transaction, the method comprising:
receiving, via a first communication channel, a first FTM message including previous FTM message departure timestamp and previous corresponding ACK message arrival timestamp; sending, via the first communication channel, a corresponding first ACK message in response to receiving the first FTM message; receiving, via the first communication channel, a second FTM message including time of departure timestamp of the first FTM message and a time of arrival timestamp for the corresponding first ACK message; sending, via the first communication channel, a corresponding second ACK message in response to receiving the second FTM message; receiving, via a second communication channel, an authenticating value indicative of the time of departure and arrival timestamp values of at least one of the first and second FTM messages and at least one of the first and second corresponding ACK messages; and authenticating the time of departure and arrival timestamps in response to evaluating the authenticating value.

16 . The computer-readable medium of claim 15 , further comprising:
recovering the timestamp values from the received authenticating value; comparing the recovered timestamp values with observed FTM-ACK time of departure and arrival timestamps; and authenticating the time of departure and arrival timestamps in response to a match between the compared timestamp values.

17 . The computer-readable medium of claim 15 , wherein receiving the authenticating value via a second communication channel comprises receiving a hash value of the timestamp values via a secure side channel.

18 . The computer-readable medium of claim 15 , wherein receiving the authenticating value via a second communication channel comprises receiving an authenticating value after transmission of each FTM-ACK message pair indicative of timestamp values of FTM and ACK message arrival and departure times.

19 . The computer-readable medium of claim 15 , wherein receiving the authenticating value via a second communication channel comprises receiving the authenticating value from

Assignees

• Texas Instruments Inc

Inventors

• Ben-Shachar Matan
• Shani Oren
• Alpert Yaron

Classifications

• H04W4/02

  Services making use of location information · CPC title

• H04L63/18

  using different networks or channels, e.g. using out of band channels (cryptographic mechanisms or cryptographic arrangements for key distribution involving distinctive intermediate devices or communication paths H04L9/0827; cryptographic mechanisms or cryptographic arrangements for authentication using a plurality of channels H04L9/3215) · CPC title

• H04W12/61

  Time-dependent · CPC title

• H04W12/06 Primary

  Authentication · CPC title

• H04L1/1678 Primary

  where the control information is for timing, e.g. time stamps · CPC title