Number Of Adversaries Research Articles

Source localization in signed networks with effective distance

While progress has been made in information source localization, it has overlooked the prevalent friend and adversarial relationships in social networks. This paper addresses this gap by focusing on source localization in signed network models. Leveraging the topological characteristics of signed networks and transforming the propagation probability into effective distance, we propose an optimization method for observer selection. Additionally, by using the reverse propagation algorithm we present a method for information source localization in signed networks. Extensive experimental results demonstrate that a higher proportion of positive edges within signed networks contributes to more favorable source localization, and the higher the ratio of propagation rates between positive and negative edges, the more accurate the source localization becomes. Interestingly, this aligns with our observation that, in reality, the number of friends tends to be greater than the number of adversaries, and the likelihood of information propagation among friends is often higher than among adversaries. In addition, the source located at the periphery of the network is not easy to identify. Furthermore, our proposed observer selection method based on effective distance achieves higher operational efficiency and exhibits higher accuracy in information source localization, compared with three strategies for observer selection based on the classical full-order neighbor coverage.

Resilient Design of Continuous-time Distributed Optimization Algorithm in the Presence of Cyber-attacks

This paper presents a continuous-time resilient distributed optimization algorithm based on competitive interaction design method on connected graphs in the presence of adversaries. The competitive interaction method allows us to design a network that protects the multi-agent systems from adversaries without requiring high network connectivity. In addition, the proposed algorithm does not require the global information about the number of adversaries. First, we show that the proposed distributed algorithm solves the resilient distributed optimization problem with no attack on the communication links. Second, we show that the proposed continuous-time distributed optimization algorithm on connected graphs converges to the small neighborhood of the optimal solution in the presence of cyber-attacks onto the communication channel. Simulations are presented to illustrate our theoretical results.

Distributed resilient consensus on general digraphs under cyber-attacks

This paper presents a distributed resilient consensus protocol based on competitive interaction design method to solve consensus problem on general digraphs containing directed spanning tree in the presence of cyber-attacks. The attacker aims at destabilizing the consensus dynamics by intercepting the systems communication network. The competitive interaction method allows us to design a virtual network that protects the multi-agent systems from adversaries without requiring high network connectivity and global information about the number of adversaries. In fact, the proposed distributed consensus protocol enables agents to achieve consensus in the presence of any number of bounded adversaries and also when the virtual network is being attacked. In addition, the proposed virtual network also improves the performance of consensus algorithm in the absence of attacks. Simulations are presented to illustrate our theoretical results.

Resilient Dynamic Average-Consensus of Multiagent Systems

This paper presents a distributed protocol based on competitive interaction design method to solve the dynamic average-consensus problem on strongly-connected balanced directed graphs in the presence of adversaries. The competitive interaction method allows us to design a network that protects the multi-agent systems from adversaries without requiring high network connectivity and global information about the number of adversaries. We design a resilient distributed protocol to track the average of time-varying bounded reference signals, which every agent is receiving. We show that in the presence of bounded cyber-attacks onto the communication network and actuators, the agents achieve dynamic average-consensus. Simulations are presented to illustrate our theoretical results.

List-Decodable Coded Computing: Breaking the Adversarial Toleration Barrier

We consider the problem of coded computing, where a computational task is performed in a distributed fashion in the presence of adversarial workers. We propose techniques to break the adversarial toleration threshold barrier previously known in coded computing. More specifically, we leverage list-decoding techniques for folded Reed-Solomon codes and propose novel algorithms to recover the correct codeword using side information. In the coded computing setting, we show how the master node can perform certain carefully designed extra computations to obtain the side information. The workload of computing this side information is negligible compared to the computations done by each worker. This side information is then utilized to prune the output of the list decoder and uniquely recover the true outcome. We further propose folded Lagrange coded computing (FLCC) to incorporate the developed techniques into a specific coded computing setting. Our results show that FLCC outperforms LCC by breaking the barrier on the number of adversaries that can be tolerated. In particular, the corresponding threshold in FLCC is improved by a factor of two asymptotically compared to that of LCC.

Reputation based Proposed Scheme to Ensure Reliable Decision by Fusion Centre

Objectives: Dynamic spectrum access is the promising feature of Cognitive Radio (CR). When Spectrum sensing is executed in a cooperative manner, shadowing and fading get reduced. Therefore, it gives an invitation to security threats. Methods/Statistical Analysis: This paper elaborates various security hazards in cognitive radio networks (CRN) along with their countermeasures. The paper elucidates the complication of Spectrum Sensing Data Falsification (SSDF) attack. The Primary objective of SSDF attack is to devastate the judgement of Fusion Centre (FC). With the aim to mitigate the influence of adversaries on the judgement given by FC, this paper proposes a scheme based on reputation and trust of cognitive users. Findings: Proposed scheme works on a well-defined strategy that will annihilate the impact of malicious users. In this FC doesn’t possess any knowledge about the number of adversaries and strategy of attack. In order to minimize the influence of adversary, implementation of clusters is considered to be a good idea. Cluster formation takes place according to specified criteria. Encryption on the sensing reports of valid clusters is exercised, with the aim to prevent from attacks such as eavesdropping etc. Parameters such as false positive rate and true detection rate can use to judge the performance of the proposed scheme. Applications/Improvements: SSDF attack is the most dangerous attack and proposed scheme not only mitigates the effect of SSDF attack but also stands strong against other dangerous attacks such as eavesdropping attack.

English

Wireless networks provide various advantages in real world. This can help businesses to increase their productivity, lower cost and effectiveness, increase scalability and improve relationship with business partners and attract customers. Communication in wireless network is critical and challenging issue. Wireless spoofing attacks are occurs easily and reduce the networks performance. Wireless spoofing attacks are easy to launch and can significantly impact the performance of networks. The flexibility and openness of wireless networks enables an adversary to masquerade as other devices easily. The traditional approach to detect spoofing attacks is to apply cryptographic authentication. Here using spatial information, a physical property of each node, so hard to falsify and not depend on cryptographic security, on the beginning for (1) detecting spoofing attacks; (2) determining the number of attackers when multiple node pretend as a same node identity, and (3) localizing multiple adversaries. Here using the correlation between a signal's spatial direction and the average received signal gain of received signal strength (RSS) inherited from wireless nodes to detect the spoofing attacks. Then the problem of determining the number of attackers as multiclass detection problem is formulated. Cluster-based mechanisms are developed to determine the number of attackers. When the training data is available, Support Vector Machines (SVM) method is used to further improve the accuracy of determining the number of attackers. The approach can both detects the presence of attacks as well as determine the number of adversaries, spoofing the same node identity, also that can localize any number of attackers and eliminate them.

Great Powers in a Restrictive International Environment

Why did Sino- American and American- Soviet engagement make greater strides in the 1969 to 1979 period than in any earlier period, resulting in significant US-Soviet negotiations on arms control, including SALT, the basic principles agreement, the Helsinki agreement, the agreement on the prevention of nuclear war, and the normalization of Sino-American relations?One explanation is thatthe United States engaged the Soviet Union and China to restore the balance between America's financial capabilities and its global commitments.2 As Henry Kissinger argues, the intent of detente was a desire to relate ends to means and our commitments to our capacities.3 Detente from this perspective was part of a broader American grand strategy to lower the cost of containment through a reduction in the number of adversaries (as Britain had done prior to World War I and World War II); negotiation on substantive issues of arms control; linkage politics to connect progress in separate issue-areas, exploiting the divisions in SinoSoviet relations; and territorial retrenchment, including the Nixon doctrine, building up regional surrogates such as Iran, and retreating from President Kennedy's two-and-a-half standard to a lesser one-and-a-half standard.The problem with this explanation is that it ignores two important aspects of this period that facilitated engagement. First, for different reasons, the leadership in Washington, Moscow, and Beijing perceived a more restrictive international environment. Had any of the leaders perceived a more permissive environment, less progress would have been made. In this environment, the strong systemic imperative meant greater clarity of the identity, magnitude, and timing of the threats, and clearer guidance about the optimal response. For the United States, engagement would lower the cost of hegemony. Engaging China would allow for retreat from Vietnam (while the US was also waging the costly war on poverty), and engaging the Soviet Union in an era of growing Soviet nuclear strategic parity would reduce the risk of a costly nuclear arms race with Moscow.For the Soviet Union, engaging the United States would lock in its emerging nuclear strategic parity, especially in long-range missile technology. Moreover, engagement would lower the threat emanating from the western European theatre, so as to allow Moscow to concentrate on the increasingly hostile Sino- Soviet front and growing instability in eastern Europe. Finally, for China, engaging the United States would create an ally to confront an ever-menacing Soviet Union. These threats included the 1968 Soviet invasion of Czechoslovakia and the subsequent Brezhnev doctrine, which established the right to intervene in another socialist state, including China; the 1969 Sino-Soviet border clashes; and the 1978 treaty of friendship and cooperation between Vietnam and the Soviet Union, which opened a second front and included the sale of military technology and the stationing of 4000 Soviet advisors on the Chinese border.4Second, American, Chinese, and Soviet leaders believed that through engagement policies (commercial, political, strategic, and military) they could enable a favourable foreign policy coalition in the other states or disable an unfavourable one.5 American leaders identified pro-western reformers, moderates, and internationalists in the political leadership or wings of power in China and the Soviet Union who were engaged in leadership struggles with hardliners. Moreover, American leaders sought to increase the size, power, and position of the moderates' domestic supporters in order to boost their domestic win-set. By enabling a favourable foreign policy coalition, Washington sought to assist the moderate leaders in realigning the foreign policies of Beijing and Moscow away from massive arms spending, extreme autarky, and war preparation.Beijing and Moscow had an interest in enabling a favourable foreign policy coalition in Washington too, though not the same coalition. …