A Modified Configurable RO PUF with Improved Security Metrics

Physical Unclonable Functions (PUF) are promising security primitives used to produce unique signature for Integrated circuit (IC) which are useful in hardware security and cryptographic applications. Out of several PUF proposed by researcher like Ring Oscillator (RO) PUF, Arbiter PUF, configurable RO (CRO) PUF etc. RO PUF is widely used because of its higher uniqueness. As the frequency of RO is highly susceptible to temperature and voltage fluctuation it affects the reliability of IC signature. So to improve the reliability configurable ROs (CRO) are used. In this paper we present a modified CRO PUF in which inverters used to design RO use different logic styles: static CMOS and Feed through logic (FTL). The FTL based CRO PUF improves the uniqueness as well as the reliability of signature against environmental fluctuation (temperature and voltage) because of its higher leakage current and low switching threshold. The security metrics like uniqueness and reliability are calculated for proposed modified CRO PUF and compared with earlier proposed CRO PUF by carrying out the simulation in 90 nm technology.