scholarly journals Doppelganger Obfuscation — Exploring theDefensive and Offensive Aspects of Hardware Camouflaging

2020 ◽  
pp. 82-108
Author(s):  
Max Hoffmann ◽  
Christof Paar
Keyword(s):  
Reverse Engineering ◽  
Low Level ◽  
Reverse Engineer ◽  
Finite State ◽  
Key Leakage ◽  
The One ◽  
High Level ◽  
Generic Design ◽  
Control Modules ◽  
First Time

Hardware obfuscation is widely used in practice to counteract reverse engineering. In recent years, low-level obfuscation via camouflaged gates has been increasingly discussed in the scientific community and industry. In contrast to classical high-level obfuscation, such gates result in recovery of an erroneous netlist. This technology has so far been regarded as a purely defensive tool. We show that low-level obfuscation is in fact a double-edged sword that can also enable stealthy malicious functionalities.In this work, we present Doppelganger, the first generic design-level obfuscation technique that is based on low-level camouflaging. Doppelganger obstructs central control modules of digital designs, e.g., Finite State Machines (FSMs) or bus controllers, resulting in two different design functionalities: an apparent one that is recovered during reverse engineering and the actual one that is executed during operation. Notably, both functionalities are under the designer’s control.In two case studies, we apply Doppelganger to a universal cryptographic coprocessor. First, we show the defensive capabilities by presenting the reverse engineer with a different mode of operation than the one that is actually executed. Then, for the first time, we demonstrate the considerable threat potential of low-level obfuscation. We show how an invisible, remotely exploitable key-leakage Trojan can be injected into the same cryptographic coprocessor just through obfuscation. In both applications of Doppelganger, the resulting design size is indistinguishable from that of an unobfuscated design, depending on the choice of encodings.

scholarly journals Gambaran Derajat Grit Pada Mahasiswa Akademi Keperawatan “X” di Kabupaten Kepulauan Aru

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Roseilla Nora Izaach
Keyword(s):  
Socioeconomic Status ◽  
Life Goals ◽  
Personality Factors ◽  
Measuring Instrument ◽  
Descriptive Data ◽  
Low Level ◽  
Validity Coefficient ◽  
Future Success ◽  
The One ◽  
High Level

This study aimed to describe the level of grit in the Nursing Academy student X in the Aru Islands. Grit is the one of the latest theory in the study of Positive Psychology which emphasizes of two important aspects are perseverance of efforts and consistency of interest, that determines the success of individuals in achieving their life goals. The goal of achieving future success through education is the reason this research is conducted. Respondents in this study were students in 2014. The number of respondents are 51 people with entirely female. Measuring instrument used in this study was grit scale consists of 12 items with reliability of 0.85 and a validity coefficient range  from 0.44 to 0.82 ( Duckworth, et.al.,2007) . Based on the results of the processing of descriptive data, it was found that the majority of respondents have a low level of grit with percentage of 86.3%. Variable aspect of grit perseverance of efforts, the majority of respondents have a low level of 90.2%, and the consistency aspect of interest, the majority of respondents have a high level of 66.7%. The socioeconomic status of the students is based on the type of work of the parents, not indicating the tendency to be related to the degree of grit. Further research that can be done is to investigate more deeply about the contribution of personality factors, differences in cultural background and demographics that affect grit. Keywords: Grit, socioeconomic status, demographics

Powered Ankle-Foot Prostheses: A Survey on Sensing Systems and Control Strategies

2019 ◽  
Author(s):  
Erik Chumacero-Polanco ◽  
James Yang
Keyword(s):  
Control Strategies ◽  
Level Control ◽  
Low Level ◽  
Kinetic Information ◽  
Sensing Systems ◽  
Systems And Control ◽  
Finite State ◽  
High Level ◽  
And Control

Abstract People who have suffered a transtibial amputation show diminished ambulation and impaired quality of life. Powered ankle foot prostheses (AFP) are used to recover some mobility of transtibial amputees (TTAs). Powered AFP is an emerging technology that has great potential to improve the quality of life of TTAs with important avenues for research and development in different fields. This paper presents a survey on sensing systems and control strategies applied to powered AFPs. Sensing kinematic and kinetic information in powered AFPs is critical for control. Ankle angle position is commonly obtained via potentiometers and encoders directly installed on the joint, velocities can be estimated using numerical differentiators, and accelerations are normally obtained via inertial measurement units (IMUs). On the other hand, kinetic information is usually obtained via strain gauges and torque sensors. On the other hand, control strategies are classified as high- and low-level control. The high-level control sets the torque or position references based on pattern generators, user’s intent of motion recognition, or finite-state machine. The low-level control usually consists of linear controllers that drive the ankle’s joint position, velocity, or torque to follow an imposed reference signal. The most widely used control strategy is the one based on finite-state machines for the high-level control combined with a proportional-derivative torque control for low-level. Most designs have been experimentally assessed with acceptable results in terms of walking speed. However, some drawbacks related to powered AFP’s weight and autonomy remain to be overcome. Future research should be focused on reducing powered AFP size and weight, increasing energy efficiency, and improving both the high- and the low-level controllers in terms of efficiency and performance.

Implementation of robotic ankle–foot orthosis with an impedance-based assist-as-needed control strategy

2021 ◽  
pp. 1-40
Author(s):  
Bing Chen ◽  
Bin Zi ◽  
Bin Zhou ◽  
Zhengyu Wang
Keyword(s):  
Level Control ◽  
Ankle Foot Orthosis ◽  
Low Level ◽  
Ankle Impedance ◽  
Torque Generation ◽  
Ankle Rehabilitation ◽  
Finite State ◽  
Proportional Derivative Controller ◽  
High Level ◽  
Foot Orthosis

Abstract In this paper, a robotic ankle–foot orthosis (AFO) is developed for individuals with a paretic ankle, and an impedance-based assist-as-needed controller is designed for the robotic AFO to provide adaptive assistance. First, a description of the robotic AFO hardware design is presented. Next, the design of the finite state machine is introduced, followed by an introduction to the modelling of the robotic AFO. Additionally, the control of the robotic AFO is presented. An impedance-based high-level controller that is composed of an ankle impedance based torque generation controller and an impedance controller is designed for the high-level control. A compensated low-level controller that is composed of a braking controller and a proportional-derivative controller with a compensation part is designed for the low-level control. Finally, a pilot study is conducted, and the experimental results demonstrate that with the proposed control algorithm, the robotic AFO has the potential for ankle rehabilitation by providing adaptive assistance. In the assisted condition with a high level of assistance, reductions of 8% and 20.1% of the root mean square of the tibialis anterior and lateral soleus activities are observed, respectively.

RECENT ADVANCES IN VIDEO CONTENT ANALYSIS: FROM VISUAL FEATURES TO SEMANTIC VIDEO SEGMENTS

2001 ◽  
Vol 01 (01) ◽  
pp. 63-81 ◽  
Author(s):  
ALAN HANJALIC ◽  
REGINALD L. LAGENDIJK ◽  
JAN BIEMOND
Keyword(s):  
Temporal Structure ◽  
Situation Comedy ◽  
Video Content ◽  
Visual Stream ◽  
Video Content Analysis ◽  
Low Level ◽  
Situation Comedies ◽  
News Program ◽  
The One ◽  
High Level

This paper addresses the problem of automatically partitioning a video into semantic segments using visual low-level features only. Semantic segments may be understood as building content blocks of a video with a clear sequential content structure. Examples are reports in a news program, episodes in a movie, scenes of a situation comedy or topic segments of a documentary. In some video genres like news programs or documentaries, the usage of different media (visual, audio, speech, text) may be beneficial or is even unavoidable for reliably detecting the boundaries between semantic segments. In many other genres, however, the pay-off in using different media for the purpose of high-level segmentation is not high. On the one hand, relating the audio, speech or text to the semantic temporal structure of video content is generally very difficult. This is especially so in "acting" video genres like movies and situation comedies. On the other hand, the information contained in the visual stream of these video genres often seems to provide the major clue about the position of semantic segments boundaries. Partitioning a video into semantic segments can be performed by measuring the coherence of the content along neighboring video shots of a sequence. The segment boundaries are then found at places (e.g., shot boundaries) where the values of content coherence are sufficiently low. On the basis of two state-of-the-art techniques for content coherence modeling, we illustrate in this paper the current possibilities for detecting the boundaries of semantic segments using visual low-level features only.

scholarly journals A Survey of Automatic Protocol Reverse Engineering Approaches, Methods, and Tools on the Inputs and Outputs View

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Baraka D. Sija ◽  
Young-Hoon Goo ◽  
Kyu-Seok Shim ◽  
Huru Hasanova ◽  
Myung-Sup Kim
Keyword(s):  
Reverse Engineering ◽  
Open Systems ◽  
Finite State Machines ◽  
Network Protocol ◽  
State Machines ◽  
Network Resources ◽  
Reverse Engineer ◽  
Open Systems Interconnection ◽  
Finite State ◽  
Protocol Reverse Engineering

A network protocol defines rules that control communications between two or more machines on the Internet, whereas Automatic Protocol Reverse Engineering (APRE) defines the way of extracting the structure of a network protocol without accessing its specifications. Enough knowledge on undocumented protocols is essential for security purposes, network policy implementation, and management of network resources. This paper reviews and analyzes a total of 39 approaches, methods, and tools towards Protocol Reverse Engineering (PRE) and classifies them into four divisions, approaches that reverse engineer protocol finite state machines, protocol formats, and both protocol finite state machines and protocol formats to approaches that focus directly on neither reverse engineering protocol formats nor protocol finite state machines. The efficiency of all approaches’ outputs based on their selected inputs is analyzed in general along with appropriate reverse engineering inputs format. Additionally, we present discussion and extended classification in terms of automated to manual approaches, known and novel categories of reverse engineered protocols, and a literature of reverse engineered protocols in relation to the seven layers’ OSI (Open Systems Interconnection) model.

scholarly journals A Bio-Inspired Integration Method for Object Semantic Representation

2016 ◽  
Vol 6 (3) ◽  
pp. 137-154 ◽  
Author(s):  
Hui Wei
Keyword(s):  
Semantic Representation ◽  
Physiological Mechanism ◽  
Semantic Gap ◽  
Symbolic Form ◽  
Low Level ◽  
Classical Receptive Field ◽  
The One ◽  
Definition Of ◽  
High Level ◽  
Almost All

Abstract We have two motivations. Firstly, semantic gap is a tough problem puzzling almost all sub-fields of Artificial Intelligence. We think semantic gap is the conflict between the abstractness of high-level symbolic definition and the details, diversities of low-level stimulus. Secondly, in object recognition, a pre-defined prototype of object is crucial and indispensable for bi-directional perception processing. On the one hand this prototype was learned from perceptional experience, and on the other hand it should be able to guide future downward processing. Human can do this very well, so physiological mechanism is simulated here. We utilize a mechanism of classical and non-classical receptive field (nCRF) to design a hierarchical model and form a multi-layer prototype of an object. This also is a realistic definition of concept, and a representation of denoting semantic. We regard this model as the most fundamental infrastructure that can ground semantics. Here a AND-OR tree is constructed to record prototypes of a concept, in which either raw data at low-level or symbol at high-level is feasible, and explicit production rules are also available. For the sake of pixel processing, knowledge should be represented in a data form; for the sake of scene reasoning, knowledge should be represented in a symbolic form. The physiological mechanism happens to be the bridge that can join them together seamlessly. This provides a possibility for finding a solution to semantic gap problem, and prevents discontinuity in low-order structures.

scholarly journals The Rhl Quorum Sensing System is at the Top of the Regulatory Hierarchy under Phosphate Limiting Conditions in Pseudomonas aeruginosa PAO1.

2020 ◽  
Author(s):  
Martín Paolo Soto-Aceves ◽  
Miguel Cocotl-Yañez ◽  
Luis Servín-González ◽  
Gloria Soberón-Chávez
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Type Strain ◽  
Phosphate Limitation ◽  
Important Approach ◽  
The One ◽  
Main Regulator ◽  
High Level ◽  
First Time

Pseudomonas aeruginosa is a major nosocomial pathogen that presents high-level resistance to antibiotics. Its ability to cause infections relies on the production of multiple virulence factors. Quorum sensing (QS) regulates the expression of many of these virulence factors through three QS systems: Las, Rhl and PQS. The Las system positively regulates the other two systems, so it is the top of a hierarchized regulation. Nevertheless, clinical and environmental strains that lack a functional Las system have been isolated and surprisingly, some of them still have the ability to produce virulence factors and infect animal models, so it has been suggested that the hierarchy could be flexible under some conditions or atypical strains. Here we analyze the PAO1 type strain and its ΔlasR-derived mutant and report for the first time a growth condition (phosphate limitation) where LasR absence has no effect either on virulence factors production nor on the gene expression profile, in contrast to a condition of phosphate repletion where the LasR hierarchy is maintained. This work provides evidence on how the QS hierarchy can change from being strictly LasR-dependent to a LasR-independent RhlR-based hierarchy under phosphate limitation even in the PAO1 type strain. IMPORTANCE Pseudomonas aeruginosa is an important pathogen considered a priority for the development of new therapeutic strategies. An important approach to fight its infections relies on blocking quorum sensing. The Las system is the main regulator of the quorum sensing response, so many research efforts aim to block this system in order to suppress the entire response. In this work we show that LasR is dispensable in a phosphate-limited environment in the PAO1 type strain, which has been used to define of the quorum-sensing response hierarchy, and that in this condition RhlR is at the top of the regulation hierarchy. These results are highly significant since phosphate-limitation represents a similar environment to the one that P. aeruginosa faces when establishing infections.

scholarly journals On the Difficulty of FSM-based Hardware Obfuscation

2018 ◽  
pp. 293-330 ◽  
Author(s):  
Marc Fyrbiak ◽  
Sebastian Wallat ◽  
Jonathan Déchelotte ◽  
Nils Albartus ◽  
Sinan Böcker ◽  
...  
Keyword(s):  
Reverse Engineering ◽  
Integrated Circuit ◽  
State Of The Art ◽  
Security Analysis ◽  
Third Party ◽  
Level Control ◽  
Finite State ◽  
Field Programmable ◽  
Ip Cores ◽  
High Level

In today’s Integrated Circuit (IC) production chains, a designer’s valuable Intellectual Property (IP) is transparent to diverse stakeholders and thus inevitably prone to piracy. To protect against this threat, numerous defenses based on the obfuscation of a circuit’s control path, i.e. Finite State Machine (FSM), have been proposed and are commonly believed to be secure. However, the security of these sequential obfuscation schemes is doubtful since realistic capabilities of reverse engineering and subsequent manipulation are commonly neglected in the security analysis. The contribution of our work is threefold: First, we demonstrate how high-level control path information can be automatically extracted from third-party, gate-level netlists. To this end, we extend state-of-the-art reverse engineering algorithms to deal with Field Programmable Gate Array (FPGA) gate-level netlists equipped with FSM obfuscation. Second, on the basis of realistic reverse engineering capabilities we carefully review the security of state-of-the-art FSM obfuscation schemes. We reveal several generic strategies that bypass allegedly secure FSM obfuscation schemes and we practically demonstrate our attacks for a several of hardware designs, including cryptographic IP cores. Third, we present the design and implementation of Hardware Nanomites, a novel obfuscation scheme based on partial dynamic reconfiguration that generically mitigates existing algorithmic reverse engineering.

Manipulation Task Planning with Constrained Kinematic Controller

2020 ◽  
Author(s):  
Marcos S. Pereira ◽  
Bruno V. Adorno
Keyword(s):  
Motion Planning ◽  
Geometric Constraints ◽  
Task Planning ◽  
Motion Controller ◽  
Planning Time ◽  
Low Level ◽  
Pick And Place ◽  
Manipulation Task ◽  
The One ◽  
High Level

This paper addresses the integration of task planning and motion control in robotic manipulation, where automatically generated feasible manipulation sequences are executed by a controller that explicitly accounts for the task geometric constraints. To cope with the high dimensionality of the manipulation problem and the complexity of specifying the tasks, we use a multi-layered framework for task and motion planning adapted from the literature. The adapted framework consists of a high-level planner, which generates task plans for linear temporal logic specifications, and a low-level motion controller, based on constrained optimization, that allows to define regions of interest instead of exact locations while being reactive to changes in theworkspace. Thus, there is no low-level motion planning time added to the total planning time. Moreover, since there is no replanning phase due to motion planner failures, the robot actions are generated only once for each task because the search for a plan occurs on a static graph. We evaluated this approach with two pick-and-place tasks with similar complexity to the original framework and showed that the number of plan nodes generated is smaller than the one in the original framework, which implies less total planning time.

scholarly journals Constraint-based automatic verification of abstract models of multithreaded programs

2007 ◽  
Vol 7 (1-2) ◽  
pp. 67-91 ◽  
Author(s):  
GIORGIO DELZANNO
Keyword(s):  
Automated Verification ◽  
Infinite Domain ◽  
Verification Method ◽  
Low Level ◽  
Multithreaded Programs ◽  
Unbounded Control ◽  
Finite State ◽  
High Level ◽  
Syntactic Restrictions ◽  
Local Variable

AbstractWe present a technique for the automated verification of abstract models of multithreaded programs providing fresh name generation, name mobility, and unbounded control. As high level specification language we adopt here an extension of communication finite-state machines with local variables ranging over an infinite name domain, called TDL programs. Communication machines have been proved very effective for representing communication protocols as well as for representing abstractions of multithreaded software. The verification method that we propose is based on the encoding of TDL programs into a low level language based on multiset rewriting and constraints that can be viewed as an extension of Petri Nets. By means of this encoding, the symbolic verification procedure developed for the low level language in our previous work can now be applied to TDL programs. Furthermore, the encoding allows us to isolate a decidable class of verification problems for TDL programs that still provide fresh name generation, name mobility, and unbounded control. Our syntactic restrictions are in fact defined on the internal structure of threads: In order to obtain a complete and terminating method, threads are only allowed to have at most one local variable (ranging over an infinite domain of names).

Sign in / Sign up

Export Citation Format

Share Document