• Journal of Sensor Science and Technology
• /
• v.27 no.1
• /
• pp.59-63
• /
• 2018

Among Internet of things (IoT) applications, the most demanding requirements for the widespread realization of many IoT visions are security and low power. In terms of security, IoT applications include tasks that are rarely addressed before such as secure computation, trusted sensing, and communication, privacy, and so on. These tasks ask for new and better techniques for the protection of data, software, and hardware. An integral part of hardware cryptographic primitives are secret keys and unique IDs. Physical Unclonable Functions(PUF) are a unique class of circuits that leverage the inherent variations in manufacturing process to create unique, unclonable IDs and secret keys. In this paper, we propose a low power Arbiter PUF circuit with low error rate and high reliability compared with conventional arbiter PUFs. The proposed PUF utilizes a power gating structure to save the power consumption in sleep mode, and uses a razor flip-flop to increase reliability. PUF has been designed and implemented using a FPGA and a ASIC chip (a 0.35 um technology). Experimental results show that our proposed PUF solves the metastability problem and reduce the power consumption of PUF compared to the conventional Arbiter PUF. It is expected that the proposed PUF can be used in systems required low power consumption and high reliability such as low power encryption processors and low power biomedical systems.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.12
• /
• pp.831-841
• /
• 2014

The attacker can access the RFID systems illegally because authentication operation on the RFID systems are performed in wireless communication. Authentication methods based on the PUF were presented to defend attacks. Because of Hash and AES, the cost is expensive for the low-cost RFID tag. In this paper, the PUF-based encryption processor and the mutual authentication protocol are proposed for low-cost RFID authentication. The challenge-response pairs (PUF's input and output) are utilized as the authentication key and encrypted by the PUF's characteristics. The encryption method is changed each session and XOR operation with random number is utilized. Therefore, it is difficult for the attacker to analyze challenge-response pairs and attack the systems. In addition, the proposed method with PUF is strong against physical attacks. And the method protects the tag cloning attack by physical attacks because there is no authentication data in the tag. Proposed processor is implemented at low cost with small footprint and low power.

• Applied Chemistry for Engineering
• /
• v.19 no.4
• /
• pp.427-431
• /
• 2008

The rigid polyurethane foams (PUF) were prepared using polyols with 90, 110, 130, and 150 isocyanate index. The effect of sea water on the physical properties of PUF with the increase in isocyanate (NCO) index and ageing time was investigated. Tensile strengths and compressive strengths of the PUFs decreased up to 10% and 7% with an increase in ageing time, respectively. Cell morphology of the PUF under sea water was turned out to be the same as that in the ambient condition. It was observed that $T_g$ and tensile modulus of the PUF under sea water increased. The results showed an additional cross-link reaction of non-reacted MDI and the change of NCO peak as observed from FT-IR spectrum.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.477-479
• /
• 2015

PUF technology is to prevent a copy of information from digital device and it can be seen whether cloning through its difference for process of implementation corresponding to wire and gate delay, etc. In this paper, multiple dielectric slabs on digital device is investigated to implement physical crypto device based on coating PUF type and its reflection characteristics is analyzed.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.5
• /
• pp.75-82
• /
• 2013

This paper presents a PUF circuit based on the randomness of crosstalk magnitudes in adjacent transmission lines. Conventional PUF circuitry suffers the reliability problem where a consistent output value is not guaranteed due to environmental changes, such as power supply voltage and operating temperature. The proposed circuit consists of three transmission lines. The crosstalk difference between two transmission line pairs can be arbitrary. The proposed circuit compares the crosstalk differences between two transmission line pairs, and yields consistent responses. The crosstalk differences are immune to operating environment changes. The proposed PUF circuit provides with reliable responses for given challenges. It can be utilized by security systems such as authentication and encryption.

• Journal of Ocean Engineering and Technology
• /
• v.36 no.4
• /
• pp.217-231
• /
• 2022

Reinforced polyurethane foam (R-PUF), a material for liquefied natural gas cargo containment systems, is expected to have different mechanical properties depending on its stacking position of foaming as the glass fiber reinforcement of R-PUF sinks inside R-PUF under the influence of gravity. In addition, since R-PUF is not a homogeneous material, it is also expected that the coordinate direction within this material has a great correlation with the mechanical properties. So, this study was conducted to confirm this correlation with the one between the mechanical properties and the stacking position. In particular, in this study, R-PUF of 3 different densities (130, 170, and 210 kg/m³) was used, and tensile, compression, and shear tests of this material were performed under 5 temperatures. As a result of the tests, it was confirmed that the strength and modulus of elasticity of the material increased as the temperature decreased. Specifically, the strength and modulus of elasticity in the Z direction, which was the lamination direction, tended to be lower than those in the other directions. Finally, the strength and elastic modulus of different specimens of the material found at the bottom of their lamination compared to the specimens with these properties found at positions other than their lamination bottom were evaluated. Further analysis confirmed that as the temperature decreased, hardening of R-PUF occurred, indicating that the strength and modulus of elasticity increased. On the other hand, as the density of R-PUF increased, a sharp increase in strength and elastic modulus of R-PUF was observed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.80-82
• /
• 2012

In this paper, we present electromagnetic modeling to design unclonable PUFs with frequency-dependant materials corresponding to Debye dispersion. To demonstrate FDTD calculations consider that 1-D problem of pulsed plane wave traveling in free space normally incident on air-silicon material interface. The pulse traveling wave at a vacuum-medium interface were reflected, and transmitted wave were dissipated. As a result, 1-D PUF with Debye dispersion material structure can be applied and FDTD calculation for PUF modeling is a good approximation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.6
• /
• pp.1141-1147
• /
• 2012

Electromagnetic analysis to design unclonable PUFs with frequency-dependant materials with Debye dispersion was considered. To simulate FDTD calculations consider that 1-D problem of pulsed plane wave traveling in free space normally incident on air-silicon material interface on dielectric substrate. The pulse traveling wave at a vacuum-medium interface was reflected, and transmitted wave was dissipated. As a result, 1-D PUF modeling with Debye dispersion on dielectric substrate structure can be applied and FDTD calculation for PUF modeling is a good approximation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.37-38
• /
• 2012

In this research, the application of PUF modeling which is configured to be doped oxide material on Si substrate and this oxide material is to prevent corrosion of the security chip device. It is to design device replication technology through applying the electromagnetic formulation and its analysis of a device and find ways to PUF design.

• Journal of Microbiology
• /
• v.45 no.3
• /
• pp.205-212
• /
• 2007

Anoxygenic photosynthesis, performed primarily by anoxygenic photosynthetic bacteria (APB), has been supposed to arise on Earth more than 3 billion years ago. The long established APB are distributed in almost every corner where light can reach. However, the relationship between APB phylogeny and source environments has been largely unexplored. Here we retrieved the pufM sequences and related source information of 89 pufM containing species from the public database. Phylogenetic analysis revealed that horizontal gene transfer (HGT) most likely occurred within 11 out of a total 21 pufM subgroups, not only among species within the same class but also among species of different phyla or subphyla. A clear source environment feature related phylogenetic distribution pattern was observed, with all species from oxic habitats and those from anoxic habitats clustering into independent subgroups, respectively. HGT among ancient APB and subsequent long term evolution and adaptation to separated niches may have contributed to the coupling of environment and pufM phylogeny.