Sound-Proximity: 2-Factor Authentication against Relay Attack on Passive Keyless Entry and Start System

Figure 5

False Negative rate and False Positive rate as a function of the threshold. (a) is the result at an outdoor parking lot, where the equal error rate is 0.0013 at a threshold of 0.273. (b) is the result at an underground parking lot, where the equal error rate is 0.0025 at a threshold of 0.315. (c) is the result at a road-side parking lot, where the equal error rate is 0.0037 at a threshold of 0.220. (d) is the result regardless of the environmental condition, where the equal error rate is 0.0024 at a threshold of 0.272.

(a) Outside parking

(b) Underground parking

(c) Road-side parking

(d) Total