PUF-FSM: A Controlled Strong PUF
This work addresses security vulnerabilities in controlled strong PUFs for applications like key generation and advanced cryptography, representing an incremental improvement over previous designs.
The paper tackles the problem of stabilizing noisy responses and preventing information leakage in controlled strong PUFs by introducing PUF-FSM, which eliminates error correction logic and helper data, using error-free responses on demand, and restricts challenge access to defend against modeling attacks.
This paper presents the PUF finite state machine (PUF-FSM) that is served as a practical {\it controlled} strong PUF. Previous controlled PUF designs have the difficulties of stabilizing the noisy PUF responses where the error correction logic is required. In addition, the computed helper data to assist error correcting, however, leaks information, which poses the controlled PUF under the threatens of fault attacks or reliability-based attacks. The PUF-FSM eschews the error correction logic and the computation, storage and loading of the helper data on-chip by only employing error-free responses judiciously determined on demand in the absence of an Arbiter PUF with a large CRP space. In addition, the access to the PUF-FSM is controlled by the trusted entity. Control in means of i) restricting challenges presented to the PUF and ii) further preventing repeated response evaluations to gain unreliability side-channel information are foundations of defensing the most powerful modeling attacks. The PUF-FSM goes beyond authentications/identifications to such as key generations and advanced cryptographic applications built upon a shared key.