PPG as a Bridge: Cross-Device Authentication for Smart Wearables with Photoplethysmography. - Jiacheng Liu; Jiankai Tang; Guangye Zhao; Ruichen Gui; Songqin Cheng; Taiting Lu; Jian Liu; Weiqiang Wang; Mahanth Gowda; Yuanchun Shi; Yuntao Wang (CoRR, 2026)