PUFRLA: A PUFBased Reliable and Lightweight Authentication Protocol Employing Binary String Shuffling Physically unclonable functions (PUFs) can be employed for device identification, authentication, secret key storage, and other security tasks. However, PUFs are susceptible to modeling attacks if a number of PUFsu0027 challengeresponse pairs (CRPs) are exposed to the adversary. Furthermore, many of the embedded devices requiring authentication have stringent resource constraints and thus require a lightweight authentication mechanism. We propose PUFRLA, a PUFbased lightweight, highly reliable authentication scheme employing binary string shuffling. The proposed scheme enhances the reliability of PUF as well as alleviates the resource constraints by employing error correction in the server instead of the device without compromising the security. The proposed PUFRLA is robust against brute force, replay, and modeling attacks. In PUFRLA, we introduce an inexpensive yet secure stream authentication scheme inside the device which authenticates the server before the underlying PUF can be invoked. This prevents an adversary from brute forcing the deviceu0027s PUF to acquire CRPs essentially locking out the device from unauthorized model generation. Additionally, we also introduce a lightweight CRP obfuscation mechanism involving XOR and shuffle operations. Results and security analysis verify that the PUFRLA is secure against brute force, replay, and modeling attacks, and provides 99% reliable authentication. In addition, PUFRLA provides a reduction of 63% and 74% for lookup tables (LUTs) and register count, respectively, in FPGA compared to a recently proposed approach while providing additional authentication advantages.

Extensive Examination of XOR Arbiter PUFs as Security Primitives for ResourceConstrained IoT Devices Communication security is essential for the proper functioning of the Internet of Things. Traditional approaches that rely on cryptographic keys are vulnerable to sidechannel attacks. Physical Unclonable Functions (PUFs), leveraging unavoidable and irreproducible variations of integrated circuits to produce responses unique for individual PUF devices, are emerging as promising candidates as security primitives to provide keyless solutions. Before a PUF can be adopted for real applications, the PUF must be thoroughly examined to understand its various properties for its application feasibility. In this paper, we study XOR PUFs for broad ranges of values for circuit architecture parameters. XOR PUFs have been extensively studied, and have been shown to be unable to withstand machine learning attacks for 64bit XOR PUFs with less than ten component PUFs. Attack methods employed in existing studies need a large number of challengeresponse pairs (CRPs), which are obtainable only if the PUF has an open access interface. When PUFembedded devices equipped with mutual authentication or response obfuscating techniques, it is difficult for attackers to accumulate large numbers of CRPs. With only a small number of accumulated CRPs available to attackers, small size PUFs, like XOR PUFs with a small number of component PUFs and stages, may become resistant to machine learning attacks. Since smaller sizes mean less resourcedemanding, it is worthwhile to examine such PUFs which have usually been considered unsafe against attacks. Such are thoughts that have been motivating us in this paper to explore the PUF performances for a wide range of values of the PUF architecture parameters.