A Graphene-Based Straintronic Physically Unclonable Function

Abstract

Physically unclonable functions (PUFs) are an integral part of modern-day hardware security. Various types of PUFs already exist, including optical, electronic, and magnetic PUFs. Here, we introduce a novel straintronic PUF (SPUF) by exploiting strain-induced reversible cracking in the contact microstructures of graphene field-effect transistors (GFETs). We found that strain cycling in GFETs with a piezoelectric gate stack and high-tensile-strength metal contacts can lead to an abrupt transition in some GFET transfer characteristics, whereas other GFETs remain resilient to strain cycling. Strain sensitive GFETs show colossal ON/OFF current ratios >10 7 , whereas strainresilient GFETs show ON/OFF current ratios <10. We fabricated a total of 25 SPUFs, each comprising 16 GFETs, and found near-ideal performance. SPUFs also demonstrated resilience to regression-based machine learning (ML) attacks in addition to supply voltage and temporal stability. Our findings highlight the opportunities for emerging straintronic devices in addressing some of the critical needs of the microelectronics industry.

Strengthening Multi‐Factor Authentication Through Physically Unclonable Functions in PVDF‐HFP‐Phase‐Dependent a‐IGZO Thin‐Film Transistors

“…To propose the advantages of the MFA feature in this study, the benchmarks in Table 1 were modeled according to the PUF types and their adopted materials. [ 12 , 86 , 87 , 88 , 89 , 90 ] Even though these security keys with the MFA can achieve further enhanced security systems rather than the one or two‐factor security system, as we know, there were no trials reporting the five steps of multi‐factor authentication at one device before us.…”

Heteronanostructured Field-Effect Transistors for Enhancing Entropy and Parameter Space in Electrical Unclonable Primitives

“…In this respect, electrical PUFs using non-silicon nanomaterials have been actively studied. − A variety of nanomaterials as entropy sources have been employed in different types of electronic devices, including transistors, FETs, resistors, and memristors (Table S1). Notable constituent nanomaterials include poly­[(2,5-bis­(2-octyldodecyl)-3,6-bis­(thien-2-yl)-pyrrolo­[3,4- c ]­pyrrole-1,4-diyl)- co -(2,2′-(2,1,3-benzothiadiazole)]-5,5′-diyl)] (PODTPPD-BT), 2,8-difluoro-5,11-bis­(triethylsilylethynyl) anthradithiophene (diF-TESADT), indium oxide, indium tin oxide (ITO), silicon nanowires, propyl pyridinium lead iodide (PrPyr­[PbI 3 ]), hafnium­(IV) oxide, , Ta/CoFeB/MgO, germanium–antimony–tellurium (GaSbTe), poly­(styrene- b -methyl methacrylate) and hydroxyl-terminated P­(S-r-MMA) random copolymer, a mixture of octadecyltrichlorosilane and 1 H ,1 H ,2 H ,2 H -perfluorodecyltriethoxysilane (ODTS/PFOTES), carbon nanotubes (CNTs), ,,, and graphene. , However, these electrical PUFs based on nanomaterials possess a restricted parameter space, often limited to a single challenge–response pair.…”

“…Insufficient randomness with low entropy is often associated with output responses that follow a Gaussian distribution in a predictable manner. A single challenge–response pair in the existing transistor-based electrical PUFs using 2D TMDCs increases vulnerability to external attacks; field effect transistor (FET)-based PUFs using bare MoS 2 or WS 2 are intrinsically disadvantaged to enhance the parameter space, due to the limited measurements of gate voltage and drain current. ,,− It should be noted that an enhanced parameter space is of paramount importance in deployable and scalable PUFs. − Unfortunately, other electrical PUFs using nanomaterials and nanostructures − have a limited parameter space (see Table S1 of Supporting Information for comprehensive comparisons).…”

Edge-by-Edge Lateral Heterostructure through Interfacial Sliding

“…We note that the material cracking−healing process at nanometer scale could provide interesting implications in the fields of flexible strain sensor 37 and hardware security. 38 Furthermore, for the healed device, we believe the reconstruction of covalent or ionic bonding is unlikely to happen during the cracking−healing process. This could be supported by the much-increased resistance (∼10-fold) of the healed structure compared to their original state without cracking.…”

“…This behavior is expected because the carrier injection is governed by the tunneling mechanism in the recontacted lateral device, while in continuous flake before cracking, the carrier is more controlled by band transport with the covalent bonded lattice. We note that the material cracking–healing process at nanometer scale could provide interesting implications in the fields of flexible strain sensor and hardware security …”