@article{wang2019hierarchical,
  title={Hierarchical identifier: application to user privacy eavesdropping on mobile payment app},
  author={Wang, Yaru and Zheng, Ning and Xu, Ming and Qiao, Tong and Zhang, Qiang and Yan, Feipeng and Xu, Jian},
  journal={Sensors},
  volume={19},
  number={14},
  pages={3052},
  year={2019},
  publisher={MDPI}
}