Patent ID: 9565187
Date: 2017-02-07
CPC Classifications: G06F,H04L,H04W

Claim:
1. A method in a first electronic device of mutual authentication between the first electronic device and a second electronic device, the method comprising: connecting to the second electronic device via a communication channel; outputting, via a speaker of the first electronic device, a first audio signal detectable by the second electronic device; receiving, from the second electronic device via the communication channel, a first estimated distance between the first electronic device and the second electronic device, the first estimated distance calculated by the second electronic device based on the first audio signal; transmitting, to the second electronic device via the communication channel, a request to output a second audio signal at a specified time; receiving, via a microphone of the first electronic device, the second audio signal, the second audio signal output by the second electronic device at the specified time; recording a receipt time corresponding to when the second audio signal is received; calculating a time difference between the specified time and the receipt time; calculating, based at least in part on the time difference, a second estimated distance between the first electronic device and the second electronic device; and determining that a difference between the first estimated distance and the second estimated distance is below a threshold amount.