Analog/mixed-signal circuits are perhaps one of the oldest and most mature fields in the IC design. However, over the past decade due to emergence of mobile and wearable devices, new paradigms in performance in terms of power, area, resolution and battery life emerged prompting new studies and techniques to improve these tradeoffs. Recently, another dimension has become increasingly important, that is, overall security of the device ranging from side-channel attack prevention to IP theft and counterfeit detection. Naturally, new circuits, systems and architectures are emerging to address these complex demands. In this talk, we will study how the traditional analog/mixed-signal solutions can be used to enhance device security, and where the traditional fails and new circuit techniques are needed.