Physical Unclonable Function

A Physical Unclonable Function (PUF) is a device that exploits inherent randomness introduced during manufacturing to give a physical entity a unique ‘fingerprint’ or trust anchor. These devices are of potential use in a variety of applications from anti-counterfeiting, identification, authentication and key generation to advanced protocols such as oblivious transfer, key exchange, key renovation and virtual proof of reality. Here we review the development of PUFs, including those that exploit optical, circuit time-delay and volatile/non-volatile memory characteristics. We examine the various applications of PUFs, and consider the security issues that they must confront, highlighting known attacks to date and potential countermeasures. We also consider the key areas for future development such as bit-specific reliability, reconfigurability and public key infrastructure (PKI).