• Journal of Internet Computing and Services
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• 제7권6호
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• pp.157-174
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• 2006

Ajax interaction model changes the posture of web application to become a stateful over HTTP. Ajax applications are long-lived inthe browser. XMLHTTPRequest (XHR) is used to facilitate the data exchange. Using HTTPS over this interaction is not viable because of the frequency of data exchange. Moreover, switching of protocols form HTTP to HTTPS for sensitive information is prohibited because of server-of-origin policy. The longevity, constraint, and asynchronous features of Ajax application need to hove a different authentication and session fondling mechanism that invoke re-authentication. This paper presents an authentication and session management scheme using Ajax. The scheme is design lo invoke periodic and event based re-authentication in the background using digest authentication with auto-generated password similar to OTP (One Time Password). The authentication and session management are wrapped into a framework called AWASec (Ajax Web Application Security) for coupling to avoid broken authentication and session management.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제38B권9호
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• pp.707-714
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• 2013

IoT, which can be regarded as an enhanced version of M2M communication technology, was proposed to realize intelligent thing to thing communications by utilizing Internet connectivity. Things in IoT are generally heterogeneous and resource constrained. Also such things are connected with each other over LLN(low power and lossy Network). Confidentiality, mutual authentication and message origin authentication are required to make a secure service in IoT. Security protocols used in traditional IP Networks cannot be directly adopted to resource constrained devices in IoT. Under the respect, a IETF standard group proposes to use lightweight version of DTLS protocol for supporting security services in IoT environments. However, the protocol can not cover up all of very constrained devices. To solve the problem, we propose a scheme which tends to support mutual authentication and session key agreement between devices that contain only a single crypto primitive module such as hash function or cipher function because of resource constrained property. The proposed scheme enhances performance by pre-computing a session key and is able to defend various attacks.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제12권2호
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• pp.65-76
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• 2002

Shin et al. proposed the new hash function with 160-bit output length at PKC'98. This hash function is based on the advantages of the existing hash functions, such as SHA-1, RIPEMD-160, HAVAL, and etc.$^{[1]}$ Recently, Han et al. cryptanalyzed the hash function proposed at PKC'98 and proposed the method finding a collision pair with $2^{-30}$ probability at FSE 2002, supposing that boolean functions satisfy SAC(Strict Avalanche Criterian).$^{[2]}$ This paper improves the method and shows that we can find a collision pair from the original version of the hash function with $2^{-37.13}$ probability through the improved method. And we point out that the problem of the function comes from shift values dependent on message.

• Convergence Security Journal
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• 제13권3호
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• pp.47-54
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• 2013

Ad-hoc network is composed of mobile nodes and has a vulnerability of attack like on conventional wire networks. So, many studies have been conducted to apply the traceback mechanism on wire network to Ad-hoc network. In this paper, a new mechanism that can trace back to IP source of spoofing DDoS packet using iTrace message on Ad-hoc network is proposed. The proposed mechanism implements ICMP Traceback message and the traceback path between agents allocated in local network and a server located in management network. Also the proposed mechanism can trace the position of attacker even after an attack is over and has extendability through standardization by using a mechanism that IETF proposed. Result of performance evaluation shows a great improvement in terms of load, integrity, safety, traceback function as compared with conventional mechanisms.

• Journal of Ecology and Environment
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• 제46권2호
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• pp.126-135
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• 2022

Background: Pollinators are important ecological elements due to their role in the maintenance of ecosystem health, wild plant reproduction, crop production and food security. The pollinator-plant interaction supports the preservation of plant and animal populations and it also improves the yield in pollination dependent crops. Having knowledge about the plant-pollinator interaction is necessary for development of pesticide risk assessment of pollinators and conservation of endangering species. Results: Traditional methods to discover the relatedness of insects and plants are based on tracing the visiting pollinators by field observations as well as palynology. These methods are time-consuming and needs expert taxonomists to identify different groups of pollinators such as insects or identify flowering plants through palynology. With pace of technology, using molecular methods become popular in identification and classification of organisms. DNA metabarcoding, which is the combination of DNA barcoding and high throughput sequencing, can be applied as an alternative method in identification of mixed origin environmental samples such as pollen loads attached to the body of insects and has been used in DNA-based discovery of plant-pollinator relationship. Conclusions: DNA metabarcoding is practical for plant-pollinator studies, however, lack of reference sequence in online databases, taxonomic resolution, universality of primers are the most crucial limitations. Using multiple molecular markers is preferable due to the limitations of developed universal primers, which improves taxa richness and taxonomic resolution of the studied community.

• Journal of the Korean Dietetic Association
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• 제12권2호
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• pp.185-199
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• 2006

The purpose of this study was to estimate the sites providing accurate and useful informations to the public by monitoring food and nutrition informations distributed through the internet quantitatively about 13 items of 7 necessary requisites. Total of 457 internet sites on the searching engines of Yahoo, Empas, Nate, Naver and Daum were monitored by 10 panels from May, 2004 to October. Thirty eight % of the sites got 7 & 8 total of 14 points and total sites showed a normal distribution. From the estimation of meta data, individual sites(5.19) were operated insufficiently compared with the commercial sites(6.10) and institutional sites(6.60) (p<0.000). According to administrators, sites were evaluated in the order of research institute> government organization> academic association> pharmaceutical company, club, food company, university> hospital> individual (p<0.000). While low-ranked sites were lack of authority because they didn't show the information provider and source, high-ranked ones lack of sustainable management(updating informations) and security. From this study, we suggest that 1) theme, contents and design have to prepared with variety to suit the need of target clients instead of that of site operator; 2) source and origin of information have to be provided; 3) informations have to be updated often and site to be managed sustainably.

• Journal of the Architectural Institute of Korea Planning & Design
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• 제35권10호
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• pp.53-62
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• 2019

The purpose of this study is to analyze the way historical heritage was dealt with during the massive urban development period of the 1960s through the case of Deoksugung Palace. The wall of Deoksugung Palace was rebuilt and relocated in 1961. Later, it was rebuilt and relocated again in 1968, and Daehanmun Gate was soon moved back too. I analyzed the opinions of the Seoul Metropolitan Government, the Cultural Heritage Committee, experts and citizens that occurred during this process and reached the following conclusion. First, in 1961, the existing stone walls of Deoksugung Palace were rebuilt rather than restored and conserved for the urbanscape at the time. Second, in the 1960s, the Cultural Heritage Committee focused on the conservation of the origin of Daehanmun Gate, while citizens valued the overall harmony and function of Deoksugung Palace. Third, unlike the 1970s project led by the president to renovate national security and national defense sites, there was a call from citizens to realize the preservation of Deoksugung Palace.

• Journal of Information Technology Applications and Management
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• 제18권3호
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• pp.61-72
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• 2011

Trust for the data created, processed and transferred on e-Science environments can be estimated with provenance. The information to form provenance, which says how the data was created and reached its current state, increases as data evolves. It is a heavy burden to trace and verify the massive provenance in order to trust data. On the other hand, it is another issue how to trust the verification of data with provenance. This paper proposes a fast and exact verification of inter-domain data transfer and data origin for e-Science environment based on PKI. The verification, which is called two-way verification, cuts down the tracking overhead of the data along the causality presented on Open Provenance Model with the domain specialty of e-Science environment supported by Grid Security Infrastructure (GSI). The proposed scheme is easy-applicable without an extra infrastructure, scalable irrespective of the number of provenance records, transparent and secure with cryptography as well as low-overhead.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제4권3호
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• pp.150-154
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• 2003

This paper designs the secure FTP model which provides origin non-repudiation and receipt non-repudiation service that sender and recipient profit of each other to prevent the repudiated of transmission of message and which provides the delivery non-repudiation service to prevent the repudiated of file reception and fact of the transmission failure of an error from the network. The FTP model which is designed to use the GSS-API and in order to have compatibility from source level, with security service it provided the interface which is consistent, establishes the secure context which application client and application server for is safe the session key which overhead from opening to the public key system with efficient key use and it used it minimized.

• The KIPS Transactions:PartC
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• 제11C권6호
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• pp.765-772
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• 2004

Multicast communication is simultaneous transmission of data to multiple receivers and saves considerably sender resources and network bandwidth. It has high risk to attack using group address and inherent complexity of routing packets to a large group of receivers. It is therefore critical to provide source authentication, allowing a receiver to ensure that received data is authentic. In this paper, we propose the multiple chain authentication scheme for secure and efficient multicast stream. To evaluate the performance of our scheme, we compare our technique with two other previously proposed schemes using simulation results. Our scheme provides non-repudiation of origin, low overhead by amortizing the signature operation over multiple packets, and high packet loss resistance.