• Journal of Information Processing Systems
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• v.1 no.1 s.1
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• pp.22-26
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• 2005

In this paper, we classified the objectionable texts into four rates according to their harmfulness and proposed the hierarchical text rating system for objectionable documents. Since the documents in the same category have similarities in used words, expressions and structure of the document, the text rating system, which uses a single classification model, has low accuracy. To solve this problem, we separate objectionable documents into several subsets by using their properties, and then classify the subsets hierarchically. The proposed system consists of three layers. In each layer, we select features using the chi-square statistics, and then the weight of the features, which is calculated by using the TF-IDF weighting scheme, is used as an input of the non-linear SVM classifier. By means of a hierarchical scheme using the different features and the different number of features in each layer, we can characterize the objectionability of documents more effectively and expect to improve the performance of the rating system. We compared the performance of the proposed system and performance of several text rating systems and experimental results show that the proposed system can archive an excellent classification performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.11
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• pp.2399-2403
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• 2011

Radio Frequency Identification(RFID) has been considered as an key infrastructure for the ubiquitous society. However, due to the inherent drawbacks, RFID causes var- ious security threats like privacy problems, tag cloning, etc. This paper analyses the security risk analysis process from the perspective of the RFID tag life cycle, identify the tag usage process, identify the associated vulnerability and threat to the confidentiality, integrity and availability of the information assets and its implications for privacy, and the mitigate the risks.

• Convergence Security Journal
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• v.7 no.3
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• pp.31-37
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• 2007

There are many investigations about the security on RFID system to protect privacy. It is important to mutual authentication of the security on RFID system. The protocol for mutual authentication use light-weight operation such as XOR operation, hash function and re-encryption. However, the protocol for authentication and privacy is required more complicated cryptography system. In this paper, we propose a mutual authentication protocol using finite field GF($2^n$) for a authentication and are a safety analysis about various attacks.

• Journal of KIISE:Databases
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• v.37 no.6
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• pp.324-332
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• 2010

The majority of event detection in real-time embedded sensor network systems is based on data fusion that uses noisy sensor data collected from complicated real-world environments. Current research has produced several excellent low-level mechanisms to collect sensor data and perform aggregation. However, solutions that enable these systems to provide real-time data processing using readings from heterogeneous sensors and subsequently detect complex events of interest in real-time fashion need further research. We are developing real-time event detection approaches which allow light-weight data fusion and do not require significant computing resources. Underlying the event detection framework is a collection of real-time monitoring and fusion mechanisms that are invoked upon the arrival of sensor data. The combination of these mechanisms and the framework has the potential to significantly improve the timeliness and reduce the resource requirements of embedded sensor networks. In addition to that, we discuss about a privacy that is foundation technique for trusted embedded sensor network system and explain anonymization technique to ensure privacy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.246-248
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• 2021

Recently data has been transformed into a data economy and society that acts as a catalyst for the development of all industries and the creation of new value, and COVID-19 is accelerating digital transformation. In the upcoming intelligent Internet of Things era, the availability of decentralized systems such as blockchain and mixnet is emerging to solve the security problems of centralized systems that makes it difficult to utilize data safely and efficiently. Blockchain manages data in a transparent and decentralized manner and guarantees the reliability and integrity of the data through agreements between participants, but the transparency of the data threatens the privacy of users. On the other hand, mixed net technology for protecting privacy protects privacy in distributed networks, but due to inefficient power consumption efficiency and processing speed issues, low cost, light weight, low power consumption Internet Hard to use. In this paper, we analyze the limitations of conventional mixed-net technology and propose a mixed-net technology method for low power consumption, high speed, and the Internet of things.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.234-235
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• 2016

With the development of the Internet, the popularization of internet has become the new trend and enormously changed the way of human communication. There is a strong need for security. The following research will provide the definition and purpose of IoT and examine its security concerns, In this paper, we surveyed at energy consumption of lightweight block ciphers implemented in reconfigurable devices, and we analyze d the effects that round unrolling might have on the energy consumed during the encryption.

• Journal of Convergence for Information Technology
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• v.10 no.4
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• pp.18-24
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• 2020

Recently, research on Society 5.0 has been actively carried out in Japan. The Society 5.0 is used in various areas using IoT sensors. This paper proposes a privacy approach model of multiple approaches to IoT users based on Society 5.0. The proposed model used multiple methods of synchronizing important information of IoT devices with one another in the virtual environment. The proposed model improved the efficiency of IoT information by accumulating the weight of IoT information on a probability-based basis. Further, it improves the accuracy of IoT information by segmenting it so that attribute information is linked to IoT information. As a result of the performance evaluation, the efficiency of IoT devices has improved by an average of 5.6 percent, depending on the number of IoT devices and the number of IoT hub devices. Accuracy has improved by an average of 15.9% depending on information collection and processing.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.177-184
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• 2006

The sensors in a ubiquitous network are limited because of the low power and ultra light weight, so many studies have revolved around the sensor. This study improves the process of the registration and authorization and suggests a way to minimize discloser of privacy by using an alias. We introduce RA(Relay Agent) for the restrict function of sensor node, and improve anonymity for private information of each sensor node by assigning alias from SM(Service Manager) in procedure of registration and authentication. The privacy of sensor node is secure in procedure of registration, authentication, and communication between nodes. We could improve the level of security with the only partial increment of computation power of RA and SM without an increase in the amount of sensor nodes.

• Journal of Internet Computing and Services
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• v.23 no.4
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• pp.73-85
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• 2022

In the era of the 4th industrial revolution, where automation and connectivity are maximized with artificial intelligence, the importance of data collection and utilization for model update is increasing. In order to create a model using artificial intelligence technology, it is usually necessary to gather data in one place so that it can be updated, but this can infringe users' privacy. In this paper, we introduce federated learning, a distributed machine learning method that can update models in cooperation without directly sharing distributed stored data, and introduce a study to optimize distributed consensus among participants without an existing server. In addition, we propose a pattern and group-based distributed consensus optimization algorithm that uses an algorithm for generating patterns and groups based on the Kirkman Triple System, and performs parallel updates and communication. This algorithm guarantees more privacy than the existing distributed consensus optimization algorithm and reduces the communication time until the model converges.

• Convergence Security Journal
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• v.7 no.1
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• pp.55-62
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• 2007

In ubiquitous environment the authentication protocol design for RFID security is studied to protect user privacy in RFID system. The XOR-based approach of RFID security is implemented inexpensively and simply. However because of using same security informations, ones of tag is disclosed easily. In this paper, we enhance the previous XOR-based authentication protocol using a circular shift operation.