Physically Unclonable Function (PUF) optical circuits are described and implemented within a Photonic Integrated Circuit (PIC) to enhance certain security properties such as device authentication, anti-tamper properties, or for use as a root-of-trust value. Optical processing is advantageous for security applications such as these since they are less susceptible to eavesdropping and side channel monitoring via the difficulty of observing electromagnetic radiation emissions during PIC operation. We employ the use of State of Output Polarization (SOP) variability arising from inherent stresses, strains and manufacturing tolerances present within a fabricated PIC. A customized optical signal processing element is used in our PUF circuit that contains a very narrow "trench" structure with tiny structural variations induced during fabrication that enhances SOP variability. The tiny structural changes in fabricated PICs are fixed resulting in repeatable SOP variation of the optical signals. To avoid a need for PUF calibration, to increase robustness with respect to input power level variation, measurement device resolution and sensitivity; we show that PUF functionality can be conveniently modeled as a discrete MultipleValued Logic (MVL) function. The proposed MVL PUF formulation avoids the need to characterize and measure exact polarization states as well as enabling the use of PUF output measurement devices that have a wide range of resolution and sensitivity specifications. Several different PUF circuits are implemented within a single fabricated PIC and are experimentally evaluated to demonstrate its efficacy.
Physically Unclonable Function (PUF) optical circuits are described and implemented within a Photonic Integrated Circuit (PIC) to enhance certain security properties such as device authentication, anti-tamper properties, or for use as a root-of-trust value. Optical processing is advantageous for security applications such as these since they are less susceptible to eavesdropping and side channel monitoring via the difficulty of observing electromagnetic radiation emissions during PIC operation. We employ the use of State of Output Polarization (SOP) variability arising from inherent stresses, strains and manufacturing tolerances present within a fabricated PIC. A customized optical signal processing element is used in our PUF circuit that contains a very narrow "trench" structure with tiny structural variations induced during fabrication that enhances SOP variability. The tiny structural changes in fabricated PICs are fixed resulting in repeatable SOP variation of the optical signals. To avoid a need for PUF calibration, to increase robustness with respect to input power level variation, measurement device resolution and sensitivity; we show that PUF functionality can be conveniently modeled as a discrete MultipleValued Logic (MVL) function. The proposed MVL PUF formulation avoids the need to characterize and measure exact polarization states as well as enabling the use of PUF output measurement devices that have a wide range of resolution and sensitivity specifications. Several different PUF circuits are implemented within a single fabricated PIC and are experimentally evaluated to demonstrate its efficacy.
Physical Unclonable Functions (PUFs) are hardware security primitives whose inherent physical complexity can be exploited for secure authentication and cryptographic key generation. Silicon photonic devices, owing to their suitability for quantum and artificial intelligence applications alongside standard CMOS fabrication processes, constitute a highly promising substrate for integrated multifunctional PUFs. Despite the advanced security guarantees offered by quantum cryptographic protocols and the central role of silicon photonics in quantum technologies, quantum readout strategies based on single-photon states for photonic PUFs remain largely unexplored. In this work, we experimentally demonstrate a silicon nitride (SiN) programmable photonic Mach Zehnder interferometer mesh that implements a unitary transformation and operates as a PUF, whose secret physical signature arises from uncontrollable waveguide variations during fabrication. Using experimentally derived parameters from the SiN integrated mesh, we further introduce and numerically evaluate a quantum readout protocol that combines single-photon states with PUFs. Maximally mixed quantum states are employed to conceal the underlying unitary transformation from passive eavesdropping. Security against adversaries possessing devices fabricated under similar conditions is assessed, with authentication performance quantified through Monte Carlo analysis of the false acceptance and false rejection rates as a function of the number of detected events and corrected errors. The results indicate exceptional performance with equal error rates as low as 10 to the minus 14, highlighting the potential of quantum secure PUFs for high security authentication applications.
Physically unclonable functions (PUFs) have emerged as a promising hardware security primitive, and recent years have seen growing interest in realizing PUFs on photonic integrated circuits (PICs). We classify existing PIC-based PUFs into electrically configured and optically encoded designs. Notably, security properties remain insufficiently analyzed, with mathematical unclonability often assumed without supporting argument. To illustrate this issue, we introduce a modeling attack against the subclass of optically encoded PUFs that operate in a linear optical regime. We show that, for a representative simulated PUF construction, observing as few as 200 challenge-response pairs allows learning the challenge-response mapping. Under canonical modeling assumptions, linear optically encoded PUFs are therefore mathematically clonable, calling for a careful assessment of their suitability for authentication protocols that rely on mathematical unclonability.
Because of advancements in digital communication and associated technology, security and privacy have become crucial. Physical Unclonable Function (PUF) is one of the promising security solutions due to their adaptability, reliability, and secure nature. PUFs are unique identifiers that can be presented in many forms due to their unique structure and application. However, their application might be limited due to the reliability and fabrication process. Hence, a new PUF is proposed in this study, which comprises a semi-distributed fiber optic device. The proposed solution can overcome reliability concerns based on the unique behavior of biosensors and offers a simple fabrication process. Based on the random information of the physical characteristics, Physical Unclonable Functions has demonstrated potential for secure device authentication. This thesis describes the design, implementation, and evaluation of semi-distributed fiber optic devices as robust PUFs. Using intrinsic variability of fiber optic interferometric configurations, each device produces a unique spectrum showing good intra-device repeatability and high inter-device differentiation. Experimental validation of spectral reflectivity measurements confirms low internal variability, crucial for reliable authentication. In addition to these correlations, this research shows extensive simulations, allowing us to thoroughly analyze device uniqueness and stability, across a broad range of environmental scenarios. The proposed semi-distributed type of the fiber optic PUFs is promising solutions for secure and scalable authentication in applications that require high levels of security and integrity. This study represents a step towards the practical deployment and enhancement of fiber-optic PUF solutions into secure systems verification.
Abstract We demonstrate the uniqueness, unclonability and secure authentication of N = 56 physical unclonable functions (PUFs) realized from silicon photonic moiré quasicrystal interferometers. Compared to prior photonic-PUF demonstrations typically limited in scale to only a handful of unique devices and on the order of 10 false authentication attempts, this work examines > 103 inter-device comparisons and false authentication attempts. Device fabrication is divided across two separate fabrication facilities, allowing for cross-fab analysis and emulation of a malicious foundry with exact knowledge of the PUF photonic circuit design and process. Our analysis also compares cross-correlation based authentication to the traditional Hamming distance method and experimentally demonstrates an authentication error rate AER = 0%, false authentication rate FAR = 0%, and an estimated probability of cloning below 10−30. This work validates the potential scalability of integrated photonic-PUFs which can attractively leverage mature wafer-scale manufacturing and automated contact-free optical probing. Such structures show promise for authenticating hardware in the untrusted supply chain or augmenting conventional electronic-PUFs to enhance system security.
The increased prevalence of the Internet of Things (IoT) and the integration of digital technology into our daily lives have given rise to heightened security risks and the need for more robust security measures. In response to these challenges, physical unclonable functions (PUFs) have emerged as promising solution, offering a highly secure method to generate unpredictable and unique random digital values by leveraging inherent physical characteristics. However, traditional PUFs implementations often require complex hardware and circuitry, which can add to the cost and complexity of the system. We present a novel approach using a random wrinkles PUF (rw-PUF) based on an optically anisotropic, facile, simple, and cost-effective material. These wrinkles contain randomly oriented liquid crystal molecules, resulting in a two-dimensional retardation map corresponding to a complex birefringence pattern. Additionally, our proposed technique allows for customization based on specific requirements using a spatial light modulator, enabling fast fabrication. The random wrinkles PUF has the capability to store multiple data sets within a single PUF without the need for physical alterations. Furthermore, we introduce a concept called 'polyhedron authentication,' which utilizes three-dimensional information storage in a voxelated random wrinkles PUF. This approach demonstrates the feasibility of implementing high-level security technology by leveraging the unique properties of the rw-PUF.
Integrated circuit anti-counterfeiting based on optical physical unclonable functions (PUFs) plays a crucial role in guaranteeing secure identification and authentication for Internet of Things (IoT) devices. While considerable efforts have been devoted to exploring optical PUFs, two critical challenges remain: incompatibility with the complementary metal-oxide-semiconductor (CMOS) technology and limited information entropy. Here, we demonstrate all-silicon multidimensionally-encoded optical PUFs fabricated by integrating silicon (Si) metasurface and erbium-doped Si quantum dots (Er-Si QDs) with a CMOS-compatible procedure. Five in-situ optical responses have been manifested within a single pixel, rendering an ultrahigh information entropy of 2.32 bits/pixel. The position-dependent optical responses originate from the position-dependent radiation field and Purcell effect. Our evaluation highlights their potential in IoT security through advanced metrics like bit uniformity, similarity, intra- and inter-Hamming distance, false-acceptance and rejection rates, and encoding capacity. We finally demonstrate the implementation of efficient lightweight mutual authentication protocols for IoT applications by using the all-Si multidimensionally-encoded optical PUFs.