Trigger Nodes Research Articles

Test Generation for Hardware Trojan Detection Using Correlation Analysis and Genetic Algorithm

Hardware Trojan (HT) is a major threat to the security of integrated circuits (ICs). Among various HT detection approaches, side channel analysis (SCA)-based methods have been extensively studied. SCA-based methods try to detect HTs by comparing side channel signatures from circuits under test with those from trusted golden references. The pre-condition for SCA-based HT detection to work is that the testers can collect extra signatures/anomalies introduced by activated HTs. Thus, activation of HTs and amplification of the differences between circuits under test and golden references are the keys to SCA-based HT detection methods. Test vectors are of great importance to the activation of HTs, but existing test generation methods have two major limitations. First, the number of test vectors required to trigger HTs is quite large. Second, the HT circuit’s activities are marginal compared with the whole circuit’s activities. In this article, we propose an optimized test generation methodology to assist SCA-based HT detection. Considering the HTs’ inherent surreptitious nature, inactive nodes with low transition probability are more likely to be selected as HT trigger nodes. Therefore, the correlations between circuit inputs and inactive nodes are first exploited to activate HTs. Then a test reordering process based on the genetic algorithm (GA) is implemented to increase the proportion of the HT circuit’s activities to the whole circuit’s activities. Experiments on 10 selected ISCAS benchmarks, wb_conmax benchmark, and b17 benchmark demonstrate that the number of test vectors required to trigger HTs reduces 28.8% on average compared with the result of MERO and MERS methods. After the test vector reordering process, the proportion of the HT circuit’s activities to the whole circuit’s activities is improved by 95% on average, compared with the result of MERS method.

A New Geo-Propagation Model of Event Evolution Chain Based on Public Opinion and Epidemic Coupling.

The online public opinion is the sum of public views, attitudes and emotions spread on major public health emergencies through the Internet, which maps out the scope of influence and the disaster situation of public health events in real space. Based on the multi-source data of COVID-19 in the context of a global pandemic, this paper analyzes the propagation rules of disasters in the coupling of the spatial dimension of geographic reality and the dimension of network public opinion, and constructs a new gravity model-complex network-based geographic propagation model of the evolution chain of typical public health events. The strength of the model is that it quantifies the extent of the impact of the epidemic area on the surrounding area and the spread of the epidemic, constructing an interaction between the geographical reality dimension and online public opinion dimension. The results show that: The heterogeneity in the direction of social media discussions before and after the “closure” of Wuhan is evident, with the center of gravity clearly shifting across the Yangtze River and the cyclical changing in public sentiment; the network model based on the evolutionary chain has a significant community structure in geographic space, divided into seven regions with a modularity of 0.793; there are multiple key infection trigger nodes in the network, with a spatially polycentric infection distribution.

Design of Trigger Circuit for High-Power Gas Switch Based on Flyback Circuit

This paper proposes a flyback-circuit-based design of a trigger circuit for a high-power gas switch. By incorporating a flyback circuit in a high-power gas switch, it is possible to generate a high step-up ratio and high-voltage pulse by using a transformer. Furthermore, simple trigger circuit having the minimum possible number of components (transformer and switch) can be realized. When an inductor is used as an energy storage element, energy is stored as a current source, and thus, the element can operate reliably when low impedance exists between the trigger node of the switch after triggering. According to the fundamental operating principle of a flyback circuit, the proposed trigger circuit is designed considering the maximum trigger voltage and energy required for a high-power gas switch. To verify the proposed design procedure and feasibility of the trigger circuit, a compact trigger circuit (7.5 kV, 1.3 mJ/pulse) is simulated using the PSpice program and implemented. Based on this compact circuit, a trigger circuit (20 kV, 100 mJ/pulse) for a triggered vacuum switch (TVS) is developed, and the tests with an actual TVS (3.3 kJ) are carried out.

On Localized Countermeasure Against Reactive Jamming Attacks in Smart Grid Wireless Mesh Networks

Reactive jamming attacks have been considered as one of the most lethal and disruptive threats to subvert or disrupt wireless networks since they attack the broadcast nature of transmission mediums by injecting interfering signals. Existing countermeasures for the Internet against reactive jamming attacks, i.e., channel surfing or frequency hopping, demands excessive computing resources, which are infeasible on the low cost resource constraint of the electrical devices in the Smart Grid wireless mesh networks. Even these are inadequate protect approaches to the control systems where the availability is the major security priority to achieve. To overcome the problems for normal lower computation power electrical devices in the Smart Grid wireless mesh networks with difference security triad from the Internet, we propose an efficient localized jamming-resistant countermeasure against the jamming attacks by the identification of trigger nodes whose wireless signal invokes the jammer in the grid. By constraining the trigger nodes to be receivers only, we can avoid the activation of the jammers and completely nullify the reactive jamming attack. The triggers identification approach utilizes a hexagon tiling coloring and sequential Group Testing (GT), which does not demand any sophisticated hardware. Theoretical analyses and simulation results endorse the suitability of our localized algorithm in terms of message and time complexity.

Deactivation of Reactive Jammers in Wireless Sensor Networks

In latest days, reactive jamming assault has emerged as a first rate security risk to wireless sensor community. Several techniques are evolved to identify the cause nodes, whose valid transmission turns on any reactive jammer. After identifying the trigger node, the node will be close all the way down to deactivate the jammer and its routing information is deleted from the routing table, then the node can’t be used again in the community. Since the node can’t be used once more within the network it's far one of the most important disadvantage. Hence to triumph over the trouble, In this paper we propose a unique technique, in which the recognized cause nodes are installed to the scanning mode, in order that we are able to reuse the trigger nodes, after deactivating the jammer node in the network. Keywords: Reactive Jamming, Jamming detection, Trigger Identification, Scanning mode.

English

A Wireless Sensor Network (WSN) is a self-configure network of sensor nodes communicate among themselves using radio signals and deployed in quantity to sense, monitor and to understand the physical world. A jammer is an entity which interferes with the physical transmission and reception of wireless communications. Reactive jamming attack is a major security problem in the wireless sensor network. The reactive jammer stays quiet when the channel is idle. The jammer starts transmitting a radio signal as soon as it senses activity on the channel. The reactive jammer nodes will be deactivated by identifying all the trigger nodes, at the same time a jammer node is localized by exploiting the changes in the neighbor nodes. The affected node can be identified, by analyzing the changes in its communication range, compared to its neighbors. The paper proposes a survey on trigger node identification and a detailed survey on techniques to identify trigger nodes and highly concentrated on the reactive jammer.

AN ENERGY EFFICIENT DEACTIVATION TECHNIQUE FOR REACTIVE JAMMERS IN WIRELESS SENSOR NETWORKS

In recent days, reactive jamming attack has emerged as a great security threat to wireless sensor network [WSN]. Several strategies are developed to identify the trigger nodes, whose legitimate transmission activates any reactive jammer. After identifying the trigger node, the node will be shut down to deactivate the jammer and its routing information is deleted from the routing table, then the node can’t be used again in the network. Since the node can’t be used again in the network it is one of the major drawbacks. Hence to overcome the problem, In this paper we propose a novel approach, where the identified trigger nodes are put in to the scanning mode, so that we can reuse the trigger nodes, after deactivating the jammer node in the network.

A Security Mechanism Against Reactive Jammer Attack In Wireless Sensor Networks Using Trigger Identification Service

Providing an efficient security for wireless sensor network is a crucial challenge which is made more difficult due to its broadcast nature and restrictions on resources such as energy, power memory usage, computation and communication capabilities. The Reactive Jammer Attack is a major security threat to wireless sensor networks because reactive jammer attack is a light weight attack which is easy to launch but difficult to detect .This work suggest a new scheme to neutralize malicious reactive jammer nodes by changing the characteristic of trigger nodes to act as only receiver. Here the current approach attempts to identify the trigger nodes using the group testing technique, which enhances the identification speed and reduces the message complexity of the status report sent periodically between the sensor nodes and the base station.

A Trigger Identification Service for Defending Reactive Jammers in WSN

During the last decade, Reactive Jamming Attack has emerged as a great security threat to wireless sensor networks, due to its mass destruction to legitimate sensor communications and difficulty to be disclosed and defended. Considering the specific characteristics of reactive jammer nodes, a new scheme to deactivate them by efficiently identifying all trigger nodes, whose transmissions invoke the jammer nodes, has been proposed and developed. Such a trigger-identification procedure can work as an application-layer service and benefit many existing reactive-jamming defending schemes. In this paper, on the one hand, we leverage several optimization problems to provide a complete trigger-identification service framework for unreliable wireless sensor networks. On the other hand, we provide an improved algorithm with regard to two sophisticated jamming models, in order to enhance its robustness for various network scenarios. Theoretical analysis and simulation results are included to validate the performance of this framework.

Simulating inter-process communication with Extended Queuing Networks

Extended Queuing Networks (EQN) are popular models for performance simulation of computer systems and communication networks. Beside the well known advantages of EQNs, inter-process communication is difficult to model. To enable functional simulation of complex hardware/software systems, we introduce two novel network elements: trigger nodes and delay nodes. The enhancement of EQNs, brought forward in this contribution, enables the simulation of non-concurrent tasks for the evaluation of non-functional system properties, like performance or power consumption. This contribution also provides implementation details and experimental results of a prototype simulator, capable of simulating Extended Queuing Networks, comprising the proposed enhancements.

The LHCb high level trigger infrastructure

The High Level Trigger and Data Acquisition system of the LHCb experiment at the CERN Large Hadron Collider must handle proton-proton collisions from beams crossing at 40 MHz. After a hardware-based first level trigger events have to be processed at the rate of 1 MHz and filtered by purely software-based trigger applications executing in a high level trigger farm consisting of up to 2000 CPUs built of commodity hardware (HLT). The final rate of accepted events is around 2 kHz. This contribution describes the architecture used to host the selection algorithms of the high level trigger on each trigger node, which is based on shared memory event buffers. It illustrates the interplay between event building processes, event filter processes and processes sending accepted events to the storage system. It describes these software components that are based on the Gaudi event processing framework.