Over the past several decades, mobile computing has changed our life style and high-performance System-on-Chip (SoC) design has been one of the key drivers in that proliferation. To improve the quality of life of more people, biomedical research including Brain-Computer Interface (BCI) has recently attracted attention. In addition, hardware security must be considered together to protect critical privacy from the malicious attacks. In this talk, I will introduce new challenges and opportunities in biomedical system and hardware security from the digital system architect point of view.