Visible Light Security 2022 - We propose a novel security communication scheme for underwater visible light communication (UVLC) based on frequency domain symmetrical zero-padding and phase scrambling. The security key is a logistic mapping generated by chaos mapping. Robust security performance is experimentally demonstrated by a PAM-8 modulated UVLC system over 1.2m underwater transmission link. The maximum data rate can be achieved at 2.025Gb/s under 7\% hard decision forward error correction (HD-FEC) limit of 3.8×10−3, clearly verifying the feasibility of the proposed scheme as a promising solution in future UVLC system.