We focus on a trait that is hard for fraudsters to manipulate: uni-directionality of communication between honest users and fraudsters. We define an accessibility score to quantify the uni-directionality and propose SkewA, a novel fraud detection method that measures the skewness in accessibility score distributions and uses it as an honesty metric.
More details can be found in the original paper (https://minjiyoon.xyz/Paper/SkewA.pdf)