• Journal of Internet Computing and Services
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• v.20 no.6
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• pp.105-117
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• 2019

Bitcoin, which can be classified as a cryptocurrency, has attracted attention from various industries because it is an innovative digital currency and the beginning of a Blockchain system. However, as the research on Bitcoin progressed, several security vulnerabilities and possible attacks were analyzed. Among them, the security problem caused by the transparency of the Blockchain database prevents the Blockchain system from being applied to various fields. This vulnerability is further classified as the weak anonymity of participating nodes and privacy problem due to disclosure of transaction details. In recent years, several countermeasures have been developed against these vulnerabilities. In this paper, we first describe the main features of the public and private Blockchain, and explain privacy, unlinkability and anonymity. And, three public Blockchain platforms, Dash, Zcash and Monero which are derived from Bitcoin, and Hyperledger Fabric which is a private Blockchain platform, are examined. And we analyze the operating principles of the protocols applied on each platform. In addition, we classify the applied technologies into anonymity and privacy protection in detail, analyze the advantages and disadvantages, and compare the features and relative performance of the platforms based on the computational speed of the applied cryptographic mechanisms.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.9
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• pp.39-45
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• 2009

When Mobile IPv6 is deployed in commercial network, a mobile node needs AAA services for an authentication, authorization and accounting. AAA and Mobile IPv6 are protocols which are operated independently. Then schemes which merge these protocols have been emerged. These schemes can enable a mobile node to establish a security association between the mobile node and a home agent and to perform a binding update for the home agent using AAA authentication request. But these schemes introduce many signal messages and long handover latency during the handover, since Route Optimization mode for Mobile Ipv6 is performed using Return Routability procedure. To solve this problem, we propose a scheme for Route Optimization mode that the home agent performs the binding update for a correspondent node via the AAA infrastructure between the home agent and the correspondent node instead of Return Routability procedure. For performance evaluation, we analyze signal message transmission costs and handover latencies during handover. We show performance improvement of the proposed scheme which reduces handover latency as 61% compared with the existing scheme.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3515-3519
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• 2016

Background: In Thailand, a national treatment protocol for childhood leukemia and lymphoma (LL) was implemented in 2006. Access to treatment has also improved with the National Health Security system. Since these innovations, survival of childhood LL has not been fully described. Materials and Methods: Trends and survival of children under 15 with childhood cancers diagnosed between 1993 and 2012 were investigated using the hospital-based data from the Khon Kaen Cancer Registry, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand. Childhood cancers were classified into 12 diagnostic groups, according to the ICCC based on the histology of the cancer. Survival rates were described by period, depending on the treatment protocol. For leukemias and lymphomas, survival was assessed for 3 periods (1993-99, 2000-5, 2006-12) while for solid tumors it was for 2 periods (before and after 2000). The impacts of sex, age, use of the national protocol, and catchment area on leukemia and lymphoma were evaluated. Overall survival was calculated using the Kaplan-Meier method while the Cox proportional hazard model was used for multivariate analysis. Trends were calculated using the R program. Results: A total of 2,343 childhood cancer cases were included. Survival for acute lymphoblastic leukemia (ALL) from 1993-9, 2000-5, and 2006-12 improved significantly (43.7%, 64.6%, and 69.9%). This was to a lesser extent true for acute non-lymphoblastic leukemia (ANLL) (28.1%, 42.0%, and 42.2%). Survival of non-Hodgkin lymphoma (NHL) also improved significantly (44%, 65.5%, and 86.8%) but not for Hodgkin disease (HD) (30.1%, 66.1%, and 70.6%). According to multivariate analysis, significant risk factors associated with poor survival in the ALL group were age under 1 and over 10 years, while not using the national protocol had hazard ratios (HR) of 1.6, 1.3, and 2.3 respectively. In NHL, only non-use of national protocols was a risk factor (HR 3.9). In ANLL and HD, none of the factors influenced survival. Survival of solid tumors (liver tumors, retinoblastomas) were significantly increased compared to after and before 2000 while survival for CNS tumors, neuroblastoma and bone tumors was not changed. Conclusions: The survival of childhood cancer in Thailand has markedly improved. Since implementation of national protocols, this is particularly the case for ALL and NHL. These results may be generalizable for the whole country.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.35-44
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• 2011

Advances in science and technology have made a lot of changes in our life. Especially, sensors have used in various ways to monitor in real time and analyze the world effectively. Traditional sensor networks, however, have used their own protocols and architecture so it had to be paid a lot of additional cost. In the past 8 years, OGC and ISO have been formulating standards and protocols for the geospatial Sensor Web. Although the OGC SWE initiatives have deployed some components, attempts have been made to access sensor data. All spatial operations had to calculate on the client side because traditional SOS architecture did not consider spatial operation for GeoSensor. As a result, clients have to implement and run spatial operations, and it caused a lot of overload on them and decreased approachableness. In this paper we propose S-SOS for in-situ and moving GeoSensor that extends 52 North SOS and provides spatialFilter and spatialFinder operations. The proposed S-SOS provides an architecture that does not need to edit already deployed SOSs and can add spatial operations as occasion. Additionally we explain how to express the spatial queries and to be used effectively for various location based services.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.8
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• pp.22-33
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• 2009

Mobile Ad Hoc Networks (MANETs) are self-organized networks that do not rely in their operation on wired infrastructure. As in any networking technology, security is an essential element in MANET as well, for proliferation of this type of networks. But supporting secure communication in MANETs proved to be a significant challenge, mainly due to the fact that the set of nodes in the network can change frequently and rapidly and due to the lack of access to the wired infrastructure. In particular, the trust model and the authentication protocols, which were developed for wired and infrastructure-based networks, cannot be used in MANETs. In [1], we addressed the problem of efficient authentication of distributed mobile users in geographically large networks and proposed a new authentication scheme for this case of MANETs. The proposed scheme exploits randomized groups to efficiently share authentication information among nodes that together implement the function of a distributive Certification Authority(CA). In this paper, we analyze numerically the performance of authentication method using randomized groups and compare with the simulation result.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1069-1073
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• 2016

The Internet of Things (IoT) is the interconnection of uniquely identifiable embedded computing devices within the existing Internet infrastructure. IoT is expected to offer advanced connectivity of devices, systems, and services that goes beyond machine-to-machine communications and covers a variety of protocols, domains, and applications. Key system-level features that IoT needs to support can be summarized as device heterogeneity, scalability, ubiquitous data exchange through proximity wireless technologies, energy optimized solutions, localization and tracking capabilities, self-organization capabilities, semantic interoperability and data management, embedded security and privacy-preserving mechanisms. Time information is a critical piece of infrastructure for any distributed system. Time information and time synchronization are also fundamental building blocks in the IoT. The IoT requires new paradigms for combining time and data. This paper reviews conventional time keeping mechanisms in the Internet and presents issues to be considered for combining time and data in the IoT.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.9
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• pp.337-346
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• 2015

There is great need for efficient user rights management method to provide a flexible service on variety protocols, domains, applications of IoT environments. In this paper, we propose a IoT service platform with CapSG to provide efficient access control for IoT various services of the environment. CapSG uses a token including authentication and access rights to perform authentication and access control service entity providing services. In addition, the generated token for service management, delegation, revocation, and provides a function such as denied. Also, it provides functions such as generation, delegation, disposal and rejection for service token management. In this paper, it provides the flexibility and efficiency of the access control for various services require of the IoT because of it is available to access control specific domain service by using the token group for each domain and is designed to access control using specific service token of tokens group.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.10
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• pp.361-372
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• 2016

Identity Privacy issues such as exposures of IMSIs(International Mobile Subscriber Identities) in access network have been consistently raised throughout GSM, UMTS, LTE in 3GPP. The 3GPP specification uses temporary identities instead of IMSI to ensure anonymity of the user. Even if temporary identities are disclosed, Identity Privacy may be maintained at a safe level by security policies such as no linkability and periodic update. But in case of IMSI, it cannot be changed even though it is exposed. There still exist some situations that IMSI is used in clear text for the authentication. Therefore, a protective mechanism for the identity confidentiality is needed. In this paper we propose a protocol based on IBE(Identity-based Encryption) to protect permanent identities in access network. By simplifying the scheme, this protocol has minimized the system impact on current 3GPP environment. And this scheme can be applied to all kind of permanent identities and 3GPP AKA(Authentication and Key Agreement) protocols in access network.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.424-434
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• 2017

In industrial wireless sensor networks, many applications require integrated QoS supporting. This paper proposes a reliable protocol for real-time monitoring in industrial wireless sensor networks. Retransmission is well-known to recover the transmission failure, however, this might cause the time delay to violate the real-time requirement. The proposed protocol exploits broadcasting feature of wireless networks and the temporal opportunity concept. The opportunities to relay the data packets are shared by the broadcasting feature and the temporal opportunity concept maximize the number of candidates in communication. Simulation results show that the proposed protocol is superior to the existing real-time protocols in term of real-time service and reliability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3865-3871
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• 2014

The U-health service provides medical services with patients anytime or anywhere and is defined as the service that combines information and communication technology with health and medical service. However, it causes some troubles, such as the disclosure of patients' medical information or data spills (personal information extrusion). Moreover, it has the weak point of the security threats associated with data based on existing wire-wireless systems because it conducts data transmission and reception through the network. Therefore, this paper suggests a safe personal information management system by designing integrated certification schema that will help compensate for the weaknesses of the U-health service. In the proposal, the protocols for user information, certification between medical institution and users, data communication encryption & decryption, and user information disuse were designed by applying the ID-Based Encryption, and analyzed such existing systems and PKI Based-based communication process, securely and safely.