Quantum computers pose a huge threat to cybersecurity, with the potential of solving complex problems in just a fraction of the time it takes to the most powerful supercomputers today. With conventional public key infrastructure (PKI) cryptography at risk, we face the task of securing our digital systems with the development of new cryptographic primitives for the post-quantum era. Inspired by nature, this project aims to developing the biometric equivalents of fingerprints and DNA for the digital world that will univocally and individually identify hardware. For this goal, Physically Unclonable Functions (PUFs) will be developed to provide hardware-based digital identifiers that will be utilised to build lightweight encryption and robust authentication procedures. But creating such unique structures is challenging in a fast-growing digital environment with increasing demand for new interconnected devices, such as the Internet of Things (IoT). To achieve this goal, we will combine light and sound. We will use ultrasound (US) waves to control the travel path of a light beam transmitted through a scattering medium to generate unique patterns. This novel method can potentially generate a high number of unique patterns while reducing the cost and complexity compared to current systems exploiting optical PUFs. The proposed device is expected to be unconditionally unclonable and, therefore, safe in the post-quantum era. This project will also explore the integration of the proposed novel PUFs with CMOS-based cryptographic primitives to create IDentity of Things (IDoT). The proposed solution is expected to be of relevance in a wide spectrum of application domains such as financial systems, medical services, energy industry, governments, and citizens