Internet-connected smart systems are everywhere – from autonomous cars to home assistants – and they’re only getting smarter. However, as edge devices process more data locally, they become prime targets for hackers, especially in the age of AI-powered attacks. A new technology developed at CUHK promises to solve that problem – by exploiting the unique physical properties of carbon nanotubes to make physically unique devices that can be reprogrammed in trillions of different ways, making hacking feel like trying to pick a lock that reshapes itself every time you touch it.