ArmSpy++: Enhanced PIN Inference through Video-based Fine-grained Arm Posture Analysis. - Dai, Huan; Chen, Yuefeng; Du, Yicong; Wang, Luping; Shao, Ziyu; Liu, Hongbo; Ren, Yanzhi; Yu, Jiadi; Liu, Bo (ACM Transactions on Privacy & Security, 2025)