Kunyang Liu

This article presents a highly stable SRAM-based physically unclonable function (PUF) using enhancement- enhancement (EE)-structure bit cells for native stability improvement. The PUF bit cells are power-gated 2-D and are normally in the OFF state, which largely reduces power and is beneficial to attack tolerance. In addition, a dark-bit detection technique based on a lightweight integrated VSS-bias generator is implemented in order to screen out potentially unstable bit cells (dark bits) induce

This article introduces an SRAM-based physically unclonable function (PUF) that employs hybrid-mode operations in the enhancement-enhancement (EE) SRAM mode and CMOS SRAM mode to achieve both high native stability and low power. A data latching scheme based on the hybrid structure enables operations under low supply voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DD</sub> ). Furthermore, the proposed hybrid SRAM PUF is compatible with hot

Strong physically unclonable functions (Strong PUFs) are expected to meet the low-energy and low-latency authentication requirements of IoT applications, owing to their exponential number of challenge-response pairs (CRPs). However, Strong PUFs suffer from vulnerability to modeling attacks and a high bit-error rate (BER). The first Strong PUF, known as the arbiter PUF, has little tolerance against modeling attacks because of the linear summation of path-delay times in its response [1]. Several s

This paper presents an Enhancement-Enhancement (EE) SRAM physically unclonable function (PUF) with a dark-bit detection technique based on an integrated Vss-bias generator. The EE SRAM PUF cell improves native stability to 0.21% bit-error rate (BER). Bit cells that are potentially unstable due to environmental variations or aging are detected via the lightweight bias generator to ensure stability, and the effectiveness is verified with experimental results of dark-bit detection performed at room

This paper presents a bit-error free SRAM-based physically unclonable function (PUF) in 130-nm standard CMOS. The PUF has a compact bitcell, with a bitcell area of 497 F2. It switches from EE SRAM to CMOS SRAM mode during evaluation, achieving high native stability, low-voltage evaluation, and low-power operation. Its stability is reinforced to 100% through hot carrier injection (HCI) burn-in on the alternate-direction nMOS load, which causes no visible oxide damage and does not require addition

Phase change materials show great promise for reducing energy consumption and relieving current energy shortage problems. Delignified wood (DW) with environmental friendliness as supporting frame can effectively mitigate leakage of phase change materials to ensure structural stability. However, conventional organic phase change/wood composites present a risk of flammability in application. Herein, we fabricate flame retardant wood-based phase change materials, in which disodium phosphate dodecah

This article presents a Strong physically unclonable function (PUF) with a 5-bit response output, which alleviates the critical issue of huge challenge-response pair (CRP) consumption for one authentication. Attack resistance is enhanced not only by improving the substitution-permutation network (SPN) using variable secret look-up tables (LUTs) and a complex permutation XOR box but also by mitigating LUT data collision and coupling Strong PUF functions between adjacent operation rounds to protec

Strong physically unclonable function (Strong PUF) [1] is a unified solution for lightweight IoT edge device authentication (Fig. 1). Although recent research made breakthroughs on the conventional issue of modeling attack vulnerability, these studies had to limit the output to 1 bit [2] –[4] or 5 bits [5] using XOR in the final stage. To generate enough response bits for one authentication period, e.g., 100 bits, either 100-time server communications (latency/energy/CRP consumption in communica

This article presents statistical modeling for bitcell mismatch shift with respect to hot carrier injection (HCI) burn-in on a static random access memory (SRAM)-based physically unclonable function (PUF). A compound distribution based on a Poisson distribution and a Gamma distribution is used to model the mismatch shift. The Poisson distribution models the number of injected hot carriers, and the Gamma distribution models the mismatch shift value induced by a certain number of injected hot carr

In this paper, a method to observe random telegraph noise in a hybrid SRAM PUF array is presented. This allows low-cost observation of RTN in a number of bitcells by applying VSS bias voltages to measure their temporal mismatches. Also, the changes in RTN amplitude after hot carrier injection burn-in, which is used for PUF stabilization, have been measured and analyzed. Experimental results from a 130-nm CMOS test chip show that the average RTN amplitude across 80-run measurements increases from

Abstract The natural polymer cellulose exhibits significant potential for various applications due to its unique optical, electronic, and chemical properties. However, the use of cellulose materials in luminescent applications has been relatively limited. This study aims to develop a simple and efficient method to enhance the fluorescence of cellulose materials by incorporating rare earth elements, thereby expanding their range of applications. In this work, we synthesized hybrid cellulose mater

Exoplanet has become one of the most popular research subjects in astronomy. This study analyzes light curve data from the K2 mission of the Kepler space telescope and measure the properties of two exoplanets, HAT-P-56 b and HATS-36 b. With the transit method, the radii are obtained, orbital periods and semi-major axes of these two exoplanets. For HAT-P-56 b, the period is , the radius is and the semi-major axis is . For HATS-36 b, the period is , the radius is and the semi-major axis is . Compa

A stable structure of tennis tower can be formed by stacking tennis balls to a certain structure. This paper will explore the structural stability of stacked tennis tower and the structural limit of the tennis tower and give the factors that limits the height growth of the tennis tower by experiments. It’s proved that the friction coefficient of tennis surface is not a constant but gradually decreases with the increase of the pressure applied. Based on this conclusion and experimental data, it i