Threshold Implementation Research Articles

Policy implementation and strategic effects: Assessing the impact of parliamentary thresholds on Indonesia’s political system and governance

This study examines the impact of parliamentary thresholds on the Indonesian political system through the lens of the Routine Policy Implementation Model and the Strategic Policy Implementation Model. The main objective is to evaluate the effectiveness of parliamentary thresholds in managing political fragmentation, assess their impact on stability and representation in the legislative system, and understand their implementation’s technical and strategic implications. Using a qualitative approach supported by interview studies and field observations, this research combines analysis of election data in the 2009, 2014, and 2019 elections with a qualitative assessment of policy changes and political dynamics. The Routine Policy Implementation Model focuses on the technical aspects of threshold implementation, including vote counting procedures and seat allocation efficiency. Meanwhile, the Strategic Policy Implementation Model examines the broader implications of these thresholds for political consolidation, government effectiveness, and the representation of minor parties. The results show that the parliamentary threshold has significantly reduced political fragmentation by consolidating the number of parties in Parliament, resulting in a legislative system that is cleaner and easier to administer. However, this consolidation has also marginalized small parties and limited political diversity. The novelty of this study lies in its comprehensive analysis of how parliamentary thresholds affect administrative efficiency and strategic political stability in Indonesia, compared to democratic countries in transition, such as Slovenia and Montenegro. In conclusion, although parliamentary thresholds have increased political stability and government effectiveness, they have also raised concerns about the reduced representation of small and regional parties. The study recommends maintaining balanced thresholds that ensure stability and diversity, implementing mechanisms to review thresholds periodically, and involving diverse stakeholders in adjusting policies to reflect evolving political dynamics. This approach will help balance the need for a stable legislative environment with broad representation.

Combined Threshold Implementation

Physical security is an important aspect of devices for which an adversary can manipulate the physical execution environment. Recently, more and more attention has been directed towards a security model that combines the capabilities of passive and active physical attacks, i.e., an adversary that performs fault-injection and side-channel analysis at the same time. Implementing countermeasures against such a powerful adversary is not only costly but also requires the skillful combination of masking and redundancy to counteract all reciprocal effects.In this work, we propose a new methodology to generate combined-secure circuits. We show how to transform Threshold Implementation (TI)-like constructions to resist any adversary with the capability to tamper with internal gates and probe internal wires. For the resulting protection scheme, we can prove the combined security in a well-established theoretical security model.Since the transformation preserves the advantages of TI-like structures, the resulting circuits prove to be more efficient in the number of required bits of randomness (up to 100%), the latency in clock cycles (up to 40%), and even the area for pipelined designs (up to 40%) than the state of the art for an adversary restricted to manipulating a single gate and probing a single wire.

Application of a quality threshold to improve liver shear wave elastography measurements in free-breathing pediatric patients.

This study assessed the benefits of quality threshold (QT) implementation for liver shear wave elastography (SWE) in children during free breathing. The QT, which adjusts the SWE map display based on shear wave quality, was set at 55%. Phantom measurements (PMs) were taken with a fixed probe using QT (termed PM-1); a moving probe without QT (PM-2); and a moving probe with QT (PM-3). Each measurement was subjected to random samplings of various sizes. Clinical measurements (CMs) were obtained from children with biliary atresia using following protocols: CM-1, manually defined regions of interest (ROIs); CM-2, default ROIs without QT; and CM-3, default ROIs with QT. Elasticity measurements were compared across fibrosis grades, and color patterns on the SWE maps were analyzed. In the phantom experiments, the moving probe produced lower elasticity measurements; this difference decreased upon QT application. With the moving probe, random sampling indicated fewer interquartile range-to-median ratios exceeding 30% upon QT application (4% vs. 14% when five values were sampled, P=0.004). In clinical experiments, QT improved the differentiation of fibrosis grade in patients over 5 years old, with a significant difference between moderate and severe fibrosis (P=0.004). Elasticity variability was positively correlated with fibrosis grade (τ=0.376, P<0.001). Certain apparent errors, termed artificial stripe patterns, were not eliminated by QT. Applying QT to exclude low-quality pixels can minimize measurement error and improve differentiation of liver fibrosis grades. The presence of an artificial stripe pattern on the SWE map may indicate images requiring exclusion.

MS-LW-TI: Primitive-Based First-Order Threshold Implementation for 4 × 4 S-boxes

Threshold implementation (TI) is a lightweight countermeasure against side-channel attacks when glitches happen. As to masking schemes, an S-box is the key part to protection. In this paper, we propose a general first-order lightweight TI scheme for 4 × 4 S-boxes and name it as MiniSat-lightweight-threshold implementation (MS-LW-TI). First, we use MiniSat to optimally decompose an S-box into the least number of three different logic gate operations, AND, OR, and XOR. Among these operations, we define two primitives and the extension of two primitives for TI design. Furthermore, we prove that the primitives and their extensions strictly comply with the security properties. Finally, we implement MS-LW-TI on Xilinx Spartan-6 Field Programmable Gate Array (FPGA) to show that the S-boxes of PRESENT, GIFT, and PICCOLO consume only 17, 15, and 13 look-up-tables (LUTs), 16, 9, and 16 flip-flops (FFs), 6, 5, and 6 slices, respectively. Compared with the existing lightweight TI design, our TI for PRESENT S-box has a 22%, 38%, and 25% reduction of LUTs, FFs, and slices to the design by Shahmirzadi and Moradi at IACR Transactions on Cryptographic Hardware and Embedded Systems (TCHES) 2021, and our TI for GIFT S-box has a 6%, 25%, and 28% reduction of LUTs, FFs, and slices to the design by Jati et al., which is the smallest.

Implications of the Presidential Threshold Implementation on the Formation of Cartel Coalitions

Implications of the Presidential Threshold Implementation on the Formation of Cartel Coalitions

Practical Randomness Effects on Physical Security in Second-Order Threshold Implementation of AES

Practical Randomness Effects on Physical Security in Second-Order Threshold Implementation of AES

StaTI: Protecting against Fault Attacks Using Stable Threshold Implementations

StaTI: Protecting against Fault Attacks Using Stable Threshold Implementations

The Relevance of Presidential Threshold Implementation in the 2024 Concurrent Elections

The strengthening of the presidential system of government in Indonesia was carried out after the amendment of the 1945 Constitution from 1999-2002. The affirmation of this presidential system is manifested, one of which is that the President is not a mandatary of the People's Consultative Assembly anymore. This is in line with the commitment of the Indonesian nation to realise a democratic rule of law. The president as the head of government is directly elected by the people. The first direct presidential election was held in 2004. In presidential elections, a threshold is applied known as the Presidential Threshold. In the 2024 election, the presidential threshold provision is still maintained where the pair of presidential candidates proposed by a political party or a combination of political parties participating in the election who meet the requirements of obtaining at least 20% of the total DPR seats or obtaining 25% of the valid votes nationally in the previous DPR member election. Presidential threshold in elections in Indonesia raises pros and cons. On the one hand, the presidential threshold can simplify political parties so as to strengthen the presidential system. In addition, the implementation of the presidential threshold can realise government stability, especially in relations between executive and legislative institutions. But on the other hand, the application of the presidential threshold in simultaneous elections needs to be reconsidered because it is based on the votes in ,the previous election. This is allegedly able to reduce the people's right to nominate alternative presidential candidates.

Information Cascades and Threshold Implementation: Theory and an Application to Crowdfunding

ABSTRACTEconomic interactions often involve sequential actions, observational learning, and contingent project implementation. We incorporate all‐or‐nothing thresholds in a canonical model of information cascades. Early supporters effectively delegate their decisions to a “gatekeeper,” resulting in unidirectional cascades without herding on rejections. Project proposers can consequently charge higher prices. Proposal feasibility, project selection, and information aggregation all improve, even when agents can wait. Equilibrium outcomes depend on crowd size, and project implementation and information aggregation achieve efficiency in the large‐crowd limit. Our key insights hold under thresholds in dollar amounts and alternative equilibrium selection, among other model extensions.

Power Side-channel Attack Resistant Circuit Designs of ARX Ciphers Using High-level Synthesis

In the Internet of Things (IoT) era, edge devices have been considerably diversified and are often designed using high-level synthesis (HLS) for improved design productivity. However, HLS tools were originally developed in a security-unaware manner, resulting in vulnerabilities to power side-channel attacks (PSCAs), which are a serious threat to IoT systems. Currently, the impact and applicability of existing methods to PSCA-resistant designs using HLS are limited. In this article, we propose an effective HLS-based design method for PSCA-resistant ciphers implemented in hardware. In particular, we focus on lightweight block ciphers composed of addition/rotation/XOR (ARX)-based permutations to study the effects of the threshold implementation (which is one of the provably secure countermeasures against PSCAs) to the behavioral descriptions of ciphers along with the changes in HLS scheduling. The results obtained using Welch’s t-test demonstrate that our proposed method can successfully improve the resistance against PSCAs for all ARX-based ciphers used as benchmarks.

New Second-order Threshold Implementation of Sm4 Block Cipher

New Second-order Threshold Implementation of Sm4 Block Cipher

Threshold Implementations in Software: Micro-architectural Leakages in Algorithms

This paper provides necessary properties to algorithmically secure firstorder maskings in scalar micro-architectures. The security notions of threshold implementations are adapted following micro-processor leakage effects which are known to the literature. The resulting notions, which are based on the placement of shares, are applied to a two-share randomness-free PRESENT cipher and Keccak-f. The assembly implementations are put on a RISC-V and an ARM Cortex-M4 core. All designs are validated in the glitch and transition extended probing model and their implementations via practical lab analysis.

Low Area and Low Power Threshold Implementation Design Technique for AES S-Box

Threshold implementation (TI) is a promising countermeasure against side-channel attacks (SCA) in the presence of glitches. However, the hardware implementation of TI in S-box needs a large number of D flip-flops to synchronize intermediate signals, which results in a large silicon area and power consumption overhead. In this brief, we present the low area and low power TI design technique for advanced encryption standard (AES) S-box. In the proposed approach, instead of using D flip-flops, low-cost synchronization circuits such as customized tri-state XOR gates, tri-state buffers, and D latches are efficiently adopted with critical path replica (CPR) circuits. As a result, the proposed TI S-box implementation with 28nm CMOS process shows up to 33.7% area and 44.3% power savings. The security of the proposed TI AES S-box against side-channel attacks is also verified with test vector leakage assessment (TVLA) tests.

Secure and Efficient Masking of Lightweight Ciphers in Software and Hardware

Abstract Masking is a well used and widely deployed countermeasure against side channel attacks, both in software and hardware. With masking comes at a great cost, search has focused on how to lower a performance penalty or find efficient masking implementation. In particular, our contribution is 2-fold: for software masking, we first find bitsliced implementations of Sbox with Multiplicative Complexity 4 and Multiplicative Depth 2, then adapt the common shares approach introduced by Coron et al. at CHES 2016 to make many cross-products $a_{i}\cdot b_{j}$ can be reuse for parallel ISW-based 32-bit nonlinear operations. Therefore, we improve the efficiency of 2$\times b/4/32$ parallel high-order masking of ISW scheme for RECTANGLE, TANGRAM and KNOT on 32-bit ARM embedded microprocessor, with roughly a 13%-34% speed-up, at cost of $(1+d) \times 32$-bit randomness. For hardware masking, 4 bit cubic Sboxes with quadratic decomposition length 2, including RECTANGLE, TANGRAM, KNOT and LWC third-round candidates, can be implemented with a 3-share and 4-share threshold implementation (TI) by decomposing cubic permutations $S$ as a composition of sub-permutations having lower algebraic degrees. We use two decomposition form: one composition of two quadratic permutations $G$ and $F$, $S = F\circ G$, is for efficiency; the other composition of some linear permutations $A_i$ and one quadratic permutation $G$, $S=A_3 \circ G \circ A_2 \circ G \circ A_1 $, is for reducing the area requirements. For $S = F\circ G$, we introduce a new approach of searching through all possible quadratic permutations $G$ with 2$^{25.71}$, which is effcient than 2$^{26.23}$ in Poschmann et al. at J. Cryptol 2011. For $S=A_3 \circ G \circ A_2 \circ G \circ A_1 $, our approach of finding $A_i$ with complexity 2$^{27.71} $, which is effcient than the method introduced by Moradi et al. at ASIACRYPT 2016. In addition, we proposes a new decomposition that $S=G \circ A_2 \circ G \circ A_1 $. We can find the fastest and the smallest hard-ware decomposition implementation of 4-bit permutations for TI with 3 and 4 shares.

A Combined Countermeasure Against Side-Channel and Fault Attack with Threshold Implementation Technique

A Combined Countermeasure Against Side-Channel and Fault Attack with Threshold Implementation Technique

Side-Channel Attack of Lightweight Cryptography Based on MixColumn: Case Study of PRINCE

Lightweight cryptography is implemented in unrolled architecture generally, which has the characteristics of low latency and high real-time performance but also faces the threat of Side-Channel Attack (SCA). Different from traditional loop architecture, the unrolled architecture requires separate protection against SCA in each round. This leads to the unrolled architecture that is very sensitive to the number of rounds that need to be protected against SCA. In this paper, we propose an optimized method for the chosen-input attack that can effectively increase the number of rounds of differential propagation and recover the key from the fourth round of unrolled PRINCE for the first time. This research also evaluates the hardware overhead and performance of two types of Threshold implementation (TI) for PRINCE. The experimental results indicate that TI imposes substantial hardware overhead on the circuit, therefore a specified number of protection rounds is required.

An Optimal Universal Construction for the Threshold Implementation of Bijective S-boxes

Threshold implementation is a method based on secret sharing to secure cryptographic ciphers (and in particular S-boxes) against differential power analysis side-channel attacks which was proposed by Nikova, Rechberger, and Rijmen in 2006. Until now, threshold implementations were only constructed for specific types of functions and some small S-boxes, but no generic construction was ever presented. In this paper, we present the first universal threshold implementation with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> +2 shares that is applicable to any bijective S-box, where <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> is its algebraic degree (or is larger than the algebraic degree). While being universal, our construction is also optimal with respect to the number of shares, since the theoretically smallest possible number, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> + 1, is not attainable for some bijective S-boxes. Our results enable low latency secure hardware implementations without the need for additional randomness. In particular, we apply this result to find two uniform sharings of the AES S-box. The first sharing is obtained by using the threshold implementation of the inversion in F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2⁸</sub> and the second by using two threshold implementations of two cubic power permutations that decompose the inversion. Area and performance figures for hardware implementations are provided.

A Threshold Implementation-Based Neural Network Accelerator With Power and Electromagnetic Side-Channel Countermeasures

With the recent advancements in machine learning (ML) theory, a lot of energy-efficient neural network (NN) accelerators have been developed. However, their associated side-channel security vulnerabilities pose a major concern. There have been several proof-of-concept attacks demonstrating the extraction of their model parameters and input data. This work introduces a threshold implementation (TI) masking-based NN accelerator that secures model parameters and inputs against power and electromagnetic (EM) side-channel attacks. The 0.159 mm2 demonstration in 28 nm runs at 125 MHz at 0.95 V and limits the area and energy overhead to 64% and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.5\times $ </tex-math></inline-formula> , respectively, while demonstrating security even greater than 2M traces. The accelerator also secures model parameters through encryption and the inputs against horizontal power analysis (HPA) attacks.

Information Cascades and Threshold Implementation: Theory and an Application to Crowdfunding

Information Cascades and Threshold Implementation: Theory and an Application to Crowdfunding

Examining the Legal Impact of Presidential Threshold Implementation in the 2024 Presidential Election

Examining the Legal Impact of Presidential Threshold Implementation in the 2024 Presidential Election