scholarly journals Stealthy Opaque Predicates in Hardware - Obfuscating Constant Expressions at Negligible Overhead

2018 ◽  
pp. 277-297 ◽  
Author(s):  
Max Hoffmann ◽  
Christof Paar
Keyword(s):  
Intellectual Property ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Static Analysis ◽  
Building Block ◽  
Hardware Trojans ◽  
Reverse Engineer ◽  
Novel Technique ◽  
Fundamental Building Block ◽  
Cryptographic Hardware

Opaque predicates are a well-established fundamental building block for software obfuscation. Simplified, an opaque predicate implements an expression that provides constant Boolean output, but appears to have dynamic behavior for static analysis. Even though there has been extensive research regarding opaque predicates in software, techniques for opaque predicates in hardware are barely explored. In this work, we propose a novel technique to instantiate opaque predicates in hardware, such that they (1) are resource-efficient, and (2) are challenging to reverse engineer even with dynamic analysis capabilities. We demonstrate the applicability of opaque predicates in hardware for both, protection of intellectual property and obfuscation of cryptographic hardware Trojans. Our results show that we are able to implement stealthy opaque predicates in hardware with minimal overhead in area and no impact on latency.

Structural and Dynamic Behavior of Pretwisted Rods and Beams

1991 ◽  
Vol 44 (12) ◽  
pp. 483-515 ◽  
Author(s):  
Aviv Rosen
Keyword(s):  
Composite Materials ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Static Analysis ◽  
High Temperatures ◽  
The Other ◽  
Present Review ◽  
Structural Elements ◽  
Coupling Effects ◽  
Very High

Because of being important structural elements in many engineering applications on one hand, and presenting inherent complicated coupling effects on the other hand, pretwisted rods have attracted the interest of many researchers. During the years, as a result of engineering breakthroughs, like the introduction of composite materials or operating at very high temperatures, the problems associated with pretwisted rods became more complicated. The present review will present the research during the last fifty years. It will be divided into three main subjects: static analysis, dynamic analysis and stability problems. The review will concentrate on the structural and dynamic aspects of pretwisted rods. Derivations of models and solution techniques will be addressed.

Dynamic analysis of a helical gear reduction by experimental and numerical methods

2020 ◽  
Vol 68 (1) ◽  
pp. 48-58
Author(s):  
Chao Liu ◽  
Zongde Fang ◽  
Fang Guo ◽  
Long Xiang ◽  
Yabin Guan ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Fourth Order ◽  
Numerical Models ◽  
Helical Gear ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Lumped Mass ◽  
Gear Mesh

Presented in this study is investigation of dynamic behavior of a helical gear reduction by experimental and numerical methods. A closed-loop test rig is designed to measure vibrations of the example system, and the basic principle as well as relevant signal processing method is introduced. A hybrid user-defined element model is established to predict relative vibration acceleration at the gear mesh in a direction normal to contact surfaces. The other two numerical models are also constructed by lumped mass method and contact FEM to compare with the previous model in terms of dynamic responses of the system. First, the experiment data demonstrate that the loaded transmission error calculated by LTCA method is generally acceptable and that the assumption ignoring the tooth backlash is valid under the conditions of large loads. Second, under the common operating conditions, the system vibrations obtained by the experimental and numerical methods primarily occur at the first fourth-order meshing frequencies and that the maximum vibration amplitude, for each method, appears on the fourth-order meshing frequency. Moreover, root-mean-square (RMS) value of the acceleration increases with the increasing loads. Finally, according to the comparison of the simulation results, the variation tendencies of the RMS value along with input rotational speed agree well and that the frequencies where the resonances occur keep coincident generally. With summaries of merit and demerit, application of each numerical method is suggested for dynamic analysis of cylindrical gear system, which aids designers for desirable dynamic behavior of the system and better solutions to engineering problems.

Immigration Dynamics and Changing Constructions of Jewish Nativeness in Israel

2019 ◽  
Author(s):  
Adane Zawdu ◽  
Sarah S. Willen
Keyword(s):  
Building Block ◽  
Social Boundaries ◽  
Institutional Practices ◽  
Political Dynamics ◽  
Fundamental Building Block ◽  
The People ◽  
Ancient Israel ◽  
State Of Israel ◽  
Historical Periods ◽  
Over Time

A fundamental building block of the Zionist vision is the claim of a primordial link between modern-day Jews and the people and territory of ancient Israel. This claim, which has proven remarkably durable despite its changing form and its tension with understandings of Palestinian indigeneity, continues to inform conceptions of nativeness in the modern-day state of Israel. This chapter explores how constructions of Jewish nativeness in Israel have changed in relation to successive immigration processes. Taking sociocultural and political dynamics as its focus, the chapter examines the cultural and institutional practices through which the notion of Jewish nativeness, its boundaries, and its logics of inclusion and exclusion were constructed and enforced in four historical periods. In each period, an increase in ethnic and religious heterogeneity challenged established notions of Jewish nativeness and membership in new ways. Although conceptions of Jewish nativeness have changed over time, they continue to shape social boundaries by signaling, and qualifying, membership in the Israeli collective.

Top-down Fabricated Gold Nanostrip on Silicon-on-insulator Wafer: A Promising Building Block towards Ultra-compact Optical Device

Nanoscale ◽  
2020 ◽  
Author(s):  
Fuping Zhang ◽  
Weikang Liu ◽  
Li Chen ◽  
Zhiqiang Guan ◽  
Hongxing Xu
Keyword(s):  
Optical Communication ◽  
Data Transmission ◽  
Building Block ◽  
High Speed ◽  
Large Data ◽  
Low Energy ◽  
Silicon On Insulator ◽  
Fundamental Building Block ◽  
Low Energy Consumption ◽  
Controllable Fabrication

he plasmonic waveguide is the fundamental building block for high speed, large data transmission capacity, low energy consumption optical communication and sensing. Controllable fabrication and simultaneously optimization of the propagation...

scholarly journals Hypervisor-assisted dynamic malware analysis

Cybersecurity ◽  
2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Roee S. Leon ◽  
Michael Kiperberg ◽  
Anat Anatey Leon Zabag ◽  
Nezer Jacob Zaidenberg
Keyword(s):  
Dynamic Analysis ◽  
Static Analysis ◽  
Cyber Security ◽  
Malware Analysis ◽  
Analysis Tools ◽  
Significant Performance

AbstractMalware analysis is a task of utmost importance in cyber-security. Two approaches exist for malware analysis: static and dynamic. Modern malware uses an abundance of techniques to evade both dynamic and static analysis tools. Current dynamic analysis solutions either make modifications to the running malware or use a higher privilege component that does the actual analysis. The former can be easily detected by sophisticated malware while the latter often induces a significant performance overhead. We propose a method that performs malware analysis within the context of the OS itself. Furthermore, the analysis component is camouflaged by a hypervisor, which makes it completely transparent to the running OS and its applications. The evaluation of the system’s efficiency suggests that the induced performance overhead is negligible.

DYNAMIC BEHAVIOR OF TELESCOPIC CRANES BOOM

2013 ◽  
Vol 13 (01) ◽  
pp. 1350010 ◽  
Author(s):  
IOANNIS G. RAFTOYIANNIS ◽  
GEORGE T. MICHALTSOS
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Analytical Model ◽  
Constant Velocity ◽  
Steel Beam ◽  
Continuum Approach ◽  
Theoretical Formulation ◽  
Modal Superposition ◽  
Superposition Technique

Telescopic cranes are usually steel beam systems carrying a load at the tip while comprising at least one constant and one moving part. In this work, an analytical model suitable for the dynamic analysis of telescopic cranes boom is presented. The system considered herein is composed — without losing generality — of two beams. The first one is a jut-out beam on which a variable in time force is moving with constant velocity and the second one is a cantilever with length varying in time that is subjected to its self-weight and a force at the tip also changing with time. As a result, the eigenfrequencies and modal shapes of the second beam are also varying in time. The theoretical formulation is based on a continuum approach employing the modal superposition technique. Various cases of telescopic cranes boom are studied and the analytical results obtained in this work are tabulated in the form of dynamic response diagrams.

ChemInform Abstract: Elucidation of Tetraboric Acid with a New Borate Fundamental Building Block in a Chiral Uranyl Fluoroborate.

ChemInform ◽  
2013 ◽  
Vol 44 (5) ◽  
pp. no-no
Author(s):  
Shuao Wang ◽  
T. Gannon Parker ◽  
Daniel J. Grant ◽  
Juan Diwu ◽  
Evgeny V. Alekseev ◽  
...  
Keyword(s):  
Building Block ◽  
Fundamental Building Block

Load-Transmitter Constraint Sets: Part I—An Effective Tool for Visualizing Load Flow in Compliant Mechanisms and Structures

2010 ◽  
Author(s):  
Girish Krishnan ◽  
Charles Kim ◽  
Sridhar Kota
Keyword(s):  
Building Block ◽  
Deformation Behavior ◽  
Design Methodology ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Load Flow ◽  
Mathematical Framework ◽  
Design Synthesis ◽  
Fundamental Building Block ◽  
Block Based

Visualizing load flow aids in conceptual design synthesis of machine components. In this paper, we present a mathematical framework to visualize load flow in compliant mechanisms and structures. This framework uses the concept of transferred forces to quantify load flow from input to the output of a compliant mechanism. The key contribution of this paper is the identification a fundamental building block known as the Load-Transmitter Constraint (LTC) set, which enables load flow in a particular direction. The transferred force in each LTC set is shown to be independent of successive LTC sets that are attached to it. This enables a continuous visualization of load flow from the input to the output. Furthermore, we mathematically relate the load flow with the deformation behavior of the mechanism. We can thus explain the deformation behavior of a number of compliant mechanisms from literature by identifying its LTC sets to visualize load flow. This method can also be used to visualize load flow in optimal stiff structure topologies. The insight obtained from this visualization tool facilitates a systematic building block based design methodology for compliant mechanisms and structural topologies.

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