Secured time of flight measurement

A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors, the instructions to configure the one or more processors to cause an apparatus of a wireless device to:

• encode a fine time measurement (FTM) request comprising a public encryption key of the wireless device for transmission to a responder;
• decode a FTM response from the responder, the FTM response comprising a public encryption key of the responder, wherein the FTM response is received at the wireless device at a time t2;
• generate a symmetric key from a private encryption key of the wireless device and the public encryption key of the responder;
• configure the wireless device to transmit an acknowledgement to the FTM response, wherein the acknowledgement is to be transmitted at a time t3;
• decode an encrypted FTM frame from the responder;
• decrypt a media access control (MAC) portion of the encrypted FTM frame with the symmetric key, the decrypted FTM message comprising a time t1 when the FTM response was transmitted and a time t4 when the acknowledgement to the FTM response was received;
• and
• determine a distance of the wireless device from the responder based on time t1, time t2, time t3, and time t4.

A method performed by an apparatus of a wireless device, the method comprising:

• encoding a fine time measurement (FTM) request comprising a public encryption key of the wireless device for transmission to a responder;
• decoding a FTM response from the responder, the FTM response comprising a public encryption key of the responder, wherein the FTM response is received at the wireless device at a time t2;
• generating a symmetric key from a private encryption key of the wireless device and the public encryption key of the responder;
• configuring the wireless device to transmit an acknowledgement to the FTM response, wherein the acknowledgement is to be transmitted at a time t3;
• decoding an encrypted FTM frame from the responder;
• decrypting a media access control (MAC) portion of the encrypted FTM frame with the symmetric key, the decrypted FTM message comprising a time t1 when the FTM response was transmitted and a time t4 when the acknowledgement to the FTM response was received;
• and
• determining a distance of the wireless device from the responder based on time t1, time t2, time t3, and time t4.

An apparatus of a first wireless device comprising:

• memory;
• and processing circuitry coupled to the memory, the processing circuitry configured to:
• decode a fine time measurement (FTM) request comprising a public encryption key of a second wireless device;
• generate a symmetric key from a private encryption key of the first wireless device and the public encryption key of the second wireless device;
• encode a FTM response to the second wireless device, the FTM response comprising a public encryption key of the first wireless device;
• configure the wireless device to transmit the FTM response to the second wireless device at a time t1;
• decode an acknowledgement from the second wireless device of the FTM response, the acknowledgment to be received at a time t4;
• encrypt t1 and t4 with the symmetric encryption key;
• encode an encrypted FTM with encrypted t1 and t4;
• and
• configure the first wireless device to transmit the encrypted FTM to the second wireless device.