Physical unclonable functions based on silicon micro-ring resonators for secure signature delegation in Wireless Sensor Networks

With the arrival of the fourth industrial revolution and the era of Cyber-Physical Systems, Wireless Sensor Networks (WSN) are employed in a large catalogue of applications, many of them critical. At the beginning, encryption techniques were enough to protect WSN, but as more sophisticated applications are proposed, protection schemes turn also more complex. In particular, schemes based on digital signatures, hash functions and Public Key Infrastructures are extensively implemented. Nevertheless, all these solutions present a very important problem: nodes must store a secret key. As future systems will be unmanaged and be deployed in remote places without surveillance, the use of ROM memories where keys are stored in a permanent way is a critical risk. Therefore, in this paper we propose a new scheme for signature delegation in WSN, based on chaotic Physical Unclonable Functions (PUF). As the size of nodes is an essential parameter to be considered, the proposed technology is supported by micro-ring resonators. A simulation scenario is also defined to validate the usability and performance of the proposed framework