Sensors are necessary for modern systems to function, as feedback about the physical world allows systems to make decisions for correct behavior. Everything from smart home devices, cars, planes, and power grids rely on sensors, and if the sensors malfunction, there can be dangerous consequences. Sensors are made up of several components on the physical layer, many of which can be influenced by physical signals such as electromagnetic radiation, acoustic waves, and light. I am exploring how these sensors may be attacked by these physical signals, potentially compromising a critical system. Then, once we know what an adversary can do, I want to find defenses to prevent these sensor attacks and build a safer future.