• Journal of the Korea Society of Computer and Information
• /
• v.25 no.3
• /
• pp.117-127
• /
• 2020

Recently, proving insurance fraud has become increasingly difficult because it occurs intentionally and secretly via organized and intelligent conspiracy by specialists such as medical personnel, maintenance companies, insurance planners, and insurance subscribers. In the case of car accidents, it is difficult to prove intentions; in particular, an insurance company with no investigation rights has practical limitations in proving the suspicions. This paper aims reveal that the detection of organized and conspired insurance fraud, which had previously been difficult, could be dramatically improved through conspiring insurance fraud detection modeling using social network analysis and visualization of the relation between suspected group entities and by seeking developmental research possibilities of data analysis techniques.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.4
• /
• pp.1594-1617
• /
• 2018

In this paper, we consider a spectrum access scenario which consists of two groups of users, namely Primary Users (PUs) and Secondary Users (SUs) in Cooperative Cognitive Radio Networks (CCRNs). SUs cooperatively relay PUs messages based on Amplify-and-Forward (AF) and Decode-and-Forward (DF) cooperative techniques, in exchange for accessing some of the spectrum for their secondary communications. From the literatures, we found that the Conventional Distributed Algorithm (CDA) and Pragmatic Distributed Algorithm (PDA) aim to maximize the PU sum-rate resulting in a lower sum-rate for the SU. In this contribution, we have investigated a suit of distributed matching algorithms. More specifically, we investigated SU-based CDA (CDA-SU) and SU-based PDA (PDA-SU) that maximize the SU sum-rate. We have also proposed the All User-based PDA (PDA-ALL), for maximizing the sum-rates of both PU and SU groups. A comparative study of CDA, PDA, CDA-SU, PDA-SU and PDA-ALL is conducted, and the strength of each scheme is highlighted. Different schemes may be suitable for different applications. All schemes are investigated under the idealistic scenario involving perfect coding and perfect modulation, as well as under practical scenario involving actual coding and actual modulation. Explicitly, our practical scenario considers the adaptive coded modulation based DF schemes for transmission flexibility and efficiency. More specifically, we have considered the Self-Concatenated Convolutional Code (SECCC), which exhibits low complexity, since it invokes only a single encoder and a single decoder. Furthermore, puncturing has been employed for enhancing the bandwidth efficiency of SECCC. As another enhancement, physical layer security has been applied to our system by introducing a unique Advanced Encryption Standard (AES) based puncturing to our SECCC scheme.

• Journal of Digital Convergence
• /
• v.14 no.10
• /
• pp.295-302
• /
• 2016

Many countries, especially ICT powers, are supporting IoT-based technology at a national level and this technology is actively being researched in the businesses and research institutes in an aim to develop technology and create an ecosystem. Roads in the Seoul city are building public facilities based on IoT to provide various services and conveniences for the users. However, for the full-fledged introduction and development of IoT, there are many cases where infringement on security and privacy and threat for life and safety happen. Also, as the IoT environment includes various environment technologies such as the existing sensor network, heterogeneous communication network, and devices optimized for the IoT environment, it inherits the existing security threat and various attack techniques. This paper researches the attribute based encryption technology for safe communication in the IoT environment. The data collected from the device is transmitted utilizing the attribute based encryption and by designing the key generation protocol, grades and authorities for the device and users are identified to transmit safe messages.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.1
• /
• pp.39-47
• /
• 2017

Nowadays, there have been an increasing number of illegal use cases where people try to fabricate the working hours by using fake fingerprints. So, the fingerprint liveness detection techniques have been actively studied and widely demanded in various applications. This paper proposes a new method to detect fake fingerprints using CNN (Convolutional Neural Ntworks) based on the patches of fingerprint images. Fingerprint image is divided into small square sized patches and each patch is classified as live, fake, or background by the CNN. Finally, the fingerprint image is classified into either live or fake based on the voting result between the numbers of fake and live patches. The proposed method does not need preprocessing steps such as segmentation because it includes the background class in the patch classification. This method shows promising results of 3.06% average classification errors on LivDet2011, LivDet2013 and LivDet2015 dataset.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.1
• /
• pp.91-101
• /
• 2017

API call sequence analysis is a kind of analysis using API call information extracted in target program. Compared to other techniques, this is advantageous as it can characterize the behavior of the target. However, existing API call sequence analysis has an issue of identifying same characteristics to different function during the analysis. To resolve the identification issue and improve performance of analysis, this study includes the method of API abstraction technique in addition to existing analysis. From there on, similarity between target programs is computed and clustered into similar types by applying LSH to abstracted API call sequence from analyzed target. Thus, this study can attribute in improving the accuracy of the malware analysis based on discovered information on the types of malware identified.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.3
• /
• pp.545-550
• /
• 2018

Ultra-lightweight block cipher CHAM, consisting of simple addition, rotation, and eXclusive-or operations, enables the efficient implementations over both low-end and high-end Internet of Things (IoT) platforms. In particular, the CHAM block cipher targets the enhanced computational performance for the low-end IoT platforms. In this paper, we introduce the efficient implementation techniques to minimize the memory consumption and optimize the execution timing over 8-bit AVR IoT platforms. To achieve the higher performance, we exploit the partly iterated expression and arrange the memory alignment. Furthermore, we exploit the optimal number of register and data update. Finally, we achieve the high RANK parameters including 29.9, 18.0, and 13.4 for CHAM 64/128, 128/128, and 128/256, respectively. These are the best implementation results in existing block ciphers.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.6
• /
• pp.2851-2873
• /
• 2016

Cloud storage as a service provides high scalability and availability as per need of user, without large investment on infrastructure. However, data security risks, such as confidentiality, privacy, and integrity of the outsourced data are associated with the cloud-computing model. Over the year's techniques such as, remote data checking (RDC), data integrity protection (DIP), provable data possession (PDP), proof of storage (POS), and proof of retrievability (POR) have been devised to frequently and securely check the integrity of outsourced data. In this paper, we improve the efficiency of PDP scheme, in terms of computation, storage, and communication cost for large data archives. By utilizing the capabilities of JAR and ZIP technology, the cost of searching the metadata in proof generation process is reduced from O(n) to O(1). Moreover, due to direct access to metadata, disk I/O cost is reduced and resulting in 50 to 60 time faster proof generation for large datasets. Furthermore, our proposed scheme achieved 50% reduction in storage size of data and respective metadata that result in providing storage and communication efficiency.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.261-269
• /
• 2009

This study was to analyze the effect of market orientation on service quality and business performance in the firms of private security guards. To attain the goal of the study described above paragraphs, some peoples held in Seoul were set as a collected group. Then, using the purposive sampling method, finally drew out and analyzed 235 peoples in total. The material collection device was the brochure named . The result of reliability check up was here below; Chronbach' $\alpha$=.732. To analyze materials, reliability analysis, SEM were used as statistic analysis techniques. The conclusion based on above study method and the result of material analysis are here below. First, market orientation have influence on service quality. Second, market orientation have influence on business performance. Third, service quality have influence on business performance.

• 전자공학회논문지 IE
• /
• v.43 no.1
• /
• pp.46-51
• /
• 2006

Recently, smart card system which is known as easy to portable and also safe from physical, electrical, and software attack is observed to manage information that becomes the target of security in safety. And java card graft upon java technology to smart card platform is having very good advantage with object-oriented techniques and also, java card have the open type OS that can show the same action in different hardware characteristic which allows various application programs. In this paper, we introduced independent execution characteristic of java platform because being set to each smart card was uncomfortable till now and we designed access control member card that allows several administrators in different access privilege by single card using java card. Several administrators can approach to various information of file type that is included on issued card to user by using different PIN. In the proposed method, confirmation of personal information, administration contents update, demand by contents, is possible by single card. At this moment, wish to do safer user certification that improve security limitation which is from PIN, used for user certification, and signature data. In the proposed method, as design and implementation of utilization technology of java card, biometrics, user certification which uses multi PIN, provide that more safety and conveniently.

• Journal of the Korea Convergence Society
• /
• v.9 no.4
• /
• pp.57-63
• /
• 2018

IoT devices are used in many areas to perform various roles and functions in a cloud environment. However, a method of access control that can stably control the IoT device has not been proposed yet. In this paper, we propose a hierarchical multi-level property access control scheme that can perform stable access of IoT devices used in a cluster environment. In order to facilitate the access of the IoT device, the proposed method not only provides the ID key (security token) unique to the IoT device by providing the IoT Hub, but also allows the IoT Hub to authenticate the X.509 certificate and the private key, So that the private key of the IoT device can not be seen outside the IoT device. As a result of the performance evaluation, the proposed method improved the authentication accuracy by 10.5% on average and the processing time by 14.3%. The overhead of IoT Hub according to the number of IoT attributes was 9.1% lower than the conventional method.