SPN-DPUF: Substitution-Permutation Network Based Secure Circuit for Digital PUF

Securing integrated circuits lifecycle requires authentication mechanisms in order to prevent counterfeiting and to prevent illegal access to private assets. Physical unclonable functions (PUFs) are good candidates to provide authentication services. However, PUFs may be sensitive to noise and environmental conditions inducing reliability issues. Digital PUFs (DPUFs), which are by design inherently robust, have recently been proposed. In this paper, we investigate the utilization, the security and the efficiency of interrogation circuitries for DPUFs. We present the concept of digital disorder based PUF primitives and related work on fabrication processes and interrogation circuitries for DPUFs, discussing their advantage and limitation. We then study the requirements to exploit this digital and reliable source of entropy and deploy a strong PUF design. We propose new models of logical layers for challenge-response mechanism based on substitution-permutation networks, which could be integrated along the randomized structure. We simulate and evaluate the different structures to estimate a first security-performance trade-off, respecting both security and resource constraints.