• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권6호
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• pp.3273-3308
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• 2017

Building appropriate trust evaluation models is an important research issue for security guarantee in social networks. Most of the existing works usually consider the trust values at the current time slot, and model trust as the stochastic variable. However, in fact, trust evolves over time, and trust is a stochastic process. In this paper, we propose a novel time-variant stochastic trust evaluation (TSTE) model, which models trust over time and captures trust evolution by a stochastic process. Based on the proposed model, we derive the time-variant bound of untrustworthy probability, which provides stochastic trust guarantee. On one hand, the time-variant trust level of each node can be measured by our model. Meanwhile, by tolerating nodes with relatively poor performance, our model can effectively improve the node resource utilization rate. Numerical simulations are conducted to verify the accuracy and consistency of the analytical bounds on distinguishing misbehaved nodes from normal ones. Moreover, simulation results on social network dataset show the tradeoff between trust level and resource utilization rate, and verify that the successful transmission rate can be improved by our model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권8호
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• pp.3926-3945
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• 2018

In Jøsang's trust model, trust evaluation is obtained through operators, but there are problems with the mutuality and asymmetry of trust and the impact of event weight on trust evaluation. Trust evaluation is updated dynamically and continuously with time and the process of interactions, but it has not been reflected in Jøsang's model. Therefore, final trust evaluation is not accurate, and malicious fraud cannot be prevented effectively. This causes the success rate of interaction to be low. To solve these problems, a new dynamic trust model is proposed based on extended subjective logic (DTM-ESL). In DTM-ESL, the event weight and the mutuality of trust are fully considered, the original one-way trust relationship is extended to a two-way trust relationship, discounting and consensus operators are improved, and trust renewal is designed based on event weight. The viability and effectiveness of this new model are verified by simulation experiments.

• International journal of advanced smart convergence
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• 제8권4호
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• pp.169-178
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• 2019

Due to the characteristics of an ad hoc network without a control center, self-organization, and flexible topology, the trust evaluation of the nodes in the network is extremely difficult. Based on the analysis of ad hoc networks and the blockchain technology, a blockchain-based node-level trust evaluation model is proposed. The concepts of the node trust degree of the HASH list on the blockchain and the perfect reward and punishment mechanism are adopted to construct the node trust evaluation model of the ad hoc network. According to the needs of different applications the network security level can be dynamically adjusted through changes in the trust threshold. The simulation experiments demonstrate that ad-hoc on-demand distance vector(AODV) Routing protocol based on this model of multicast-AODV(MAODV) routing protocol shows a significant improvement in security compared with the traditional AODV and on-demand multipath distance vector(AOMDV) routing protocols.

• Journal of Information Processing Systems
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• 제16권6호
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• pp.1281-1292
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• 2020

More and more cloud computing services are being applied in various fields; however, it is difficult for users and cloud computing service platforms to establish trust among each other. The trust value cannot be measured accurately or effectively. To solve this problem, we design a service-oriented cloud trust assessment model using a cloud model. We also design a subjective preference weight allocation (SPWA) algorithm. A flexible weight model is advanced by combining SPWA with the entropy method. Aiming at the fuzziness and subjectivity of trust, the cloud model is used to measure the trust value of various cloud computing services. The SPWA algorithm is used to integrate each evaluation result to obtain the trust evaluation value of the entire cloud service provider.

• 한국지능시스템학회논문지
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• 제16권1호
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• pp.61-65
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• 2006

이 논문에서는 개체에 대한 신뢰도를 계산하기 위해 여러 가지의 평가기준을 이용하고, 또한 다른 개체들로 부터의 추천정보를 이용하는 신뢰모델에 대해서 제안한다. 제안한 모델에서는 개체의 신뢰도를 개체가 주어진 상황에서 만족스러운 결과를 낼 기대값으로 정의한다. 다른 개체와 상호작용이 일어날 때마다 각 평가기준에 빠른 평가결과가 얻어진다고 전제하는 상황에서 적용되는 신뢰 모델이다. 제안한 모델에서는 신뢰정보가 요구될 때 우선 결과확률 분포와 개체의 평가결과에 대한 선호도를 고려하여 각 평가기준에 대한 만족정도를 계산한때, 이렇게 계산된 만족정도 값들은 각 평가기준의 중요를 반영하여 하나의 신뢰값으로 결합된다. 이때 추천 정보도 신뢰값에 함께 결합되는 모델이다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권5호
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• pp.2396-2413
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• 2018

Trust management is one of the most challenging issues for the highly heterogeneous Internet of Things (IoT). In the context of the IoT, it is difficult to evaluate the node's trustworthiness in the same trust model when a node provides different services. Guaranteeing the availability of the trust management service is another significant challenge because of the dynamic nature of IoT environments. With these issues in mind, this paper propose a robust and adaptive trust management system for the IoT that is able to measure the trustworthiness of nodes based on feedbacks collected from participants in a specific context and ensure the availability of trust management services. The main contributions of our system are: 1) Proposing a partly decentralized trust management framework, which improves the resiliency of the trust mechanism; 2) Proposing an adaptive trust evaluation scheme and a three-dimensional context representation makes trust evaluation more accurate and specific; 3) Enhancing the adaptive trust evaluation scheme by incorporating a bad behavior factor in trust estimation, which efficiently distinguishes misleading feedbacks from On-Off attacks. Simulation results show the good performance of the proposed system and especially show effectiveness against On-Off attacks compared to other trust mechanisms.

• 한국지능시스템학회논문지
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• 제16권6호
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• pp.653-658
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• 2006

신뢰는 다른 상대가 특정한 행동을 할 것이라고 믿는 정도를 나타내는 주관적인 확률값으로 정의할 수 있다. 본 논문에서는 신뢰값을 결정하는 데서 고려되는 기질신뢰, 일반신뢰, 상황신뢰를 모두 고려하고, 또한 상대에 대한 명성정보를 이용하는 종합적인 퍼지 신뢰모델을 제안한다. 제안한 모델은 거래에 대한 평가결과들에 대해서 만족하는 정도를 퍼지집합으로 나타내고 평가 항목에 대한 중요도를 ${\lambda}$-퍼지측도의 성질을 만족하도록 설정하고, 평가항목별 만족정도를 Sugeno 퍼지적분을 이용하여 결합하는 방법을 사용한다.

• Journal of Information Processing Systems
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• 제17권1호
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• pp.136-150
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• 2021

The modern market is highly competitive. It has progressed from traditional competition between enterprises to competition between supply chains. To ensure that enterprise can form the best strategy consistently, it is necessary to evaluate the trust of other enterprises in the supply chain. First, this paper analyzes the background and significance of supply chain trust research, analyzes and expounds on the qualitative and quantitative methods of supply chain trust evaluation, and summarizes the research in this field. Analytic hierarchy process (AHP) is the most frequently used method in the literature to evaluate and rank criteria through data analysis. However, the input data for AHP analysis is based on human judgment, and hence there is every possibility that the data may be vague to some extent. Therefore, in view of the above problems, this study improves the global trust method based on chain iteration. The improved global trust evaluation method based on chain iteration is more flexible and practical, hence, it can more accurately evaluate supply chain trust. Finally, combined with an actual case of Zhaoxian Chengji Food Co. Ltd., the paper qualitatively analyzes the current situation of supply chain trust management and effectively strengthens the supervision of enterprises to cooperative enterprises. Thus, the company can identify problems on time and strategic adjustments can be implemented accordingly. The effectiveness of the evaluation method proposed in this paper is demonstrated through a quantitative evaluation of its trust in downstream enterprise A. Results suggest that the subjective preferences of and historical transactions together affect the final evaluation of trust.

• 품질경영학회지
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• 제34권2호
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• pp.33-47
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• 2006

This study was designed to examine the casual relationships among trust evaluation factors, trust, customer satisfaction, and re-use intention in the P2P file sharing service. We applied structural equation model to test the hypotheses and research model. As a result of this study, trust evaluation factors affect trust and customer satisfaction and both of trust and customer satisfaction affect re-use intention respectively and significantly. Also trust affects customer satisfaction significantly. Specifically, trust was empirically confirmed as one of the important factors preceding customer satisfaction and re-use intetion in the P2P file sharing service. Therefore, this study shows that trust is important factor that P2P companies have to emphasize to raise user satisfaction and performance.

• 디지털산업정보학회논문지
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• 제4권1호
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• pp.33-40
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• 2008

This paper presents a new scheduling scheme in wireless distributed network. To overcome the limited information about unfamiliar mobile nodes and to reduce the required system performance, we propose a scheduling algorithm of job allocation based on the trust model. The suggested scheduler evaluate an unfamiliar mobile node's trust and make reference to the trust value of neighboring scheduler. This scheduling algorithm can avoid malicious or selfish mobile nodes by assigning low trust values. We also present a trust evaluation metric and show the efficiency of suggested scheduling algorithm by performance evaluation.