• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1938-1962
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• 2015

Security of information during transmission is a major issue in this modern era. All of the communicating bodies want confidentiality, integrity, and authenticity of their secret information. Researchers have presented various schemes to cope with these Internet security issues. In this context, both steganography and cryptography can be used effectively. However, major limitation in the existing steganographic methods is the low-quality output stego images, which consequently results in the lack of security. To cope with these issues, we present an efficient method for RGB images based on gray level modification (GLM) and multi-level encryption (MLE). The secret key and secret data is encrypted using MLE algorithm before mapping it to the grey-levels of the cover image. Then, a transposition function is applied on cover image prior to data hiding. The usage of transpose, secret key, MLE, and GLM adds four different levels of security to the proposed algorithm, making it very difficult for a malicious user to extract the original secret information. The proposed method is evaluated both quantitatively and qualitatively. The experimental results, compared with several state-of-the-art algorithms, show that the proposed algorithm not only enhances the quality of stego images but also provides multiple levels of security, which can significantly misguide image steganalysis and makes the attack on this algorithm more challenging.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.233-239
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• 2014

Ultra high-resolution content, the file size is very large, therefore existing encoding techniques, it is not possible to transmit via the network. Efficient use of the network encoder HEVC corporation can be transferred. Compression requires a lot of time because it requires a distributed transcoding system. Distributed transcoding system is a distributed data store, and then encoded using a large number of nodes. The disadvantage of distributed transcoding system for distributed information is exposed or vulnerable to attack by internal managers. In this paper, when the super high definition content transcoding, distributed transcoding system does not guarantee the confidentiality of the problem to solve. We are using SNA, HEVC encoded content data encrypted using the secret distributing scheme was. Consequently, secure shared transcoding is possible, the internal administrator could prevent the attack.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.190-195
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• 2018

Recently, Due to the ongoing increase in cyber attacks and the improved awareness of privacy protection, most Internet services encrypt the traffic by using security protocols. Existing security protocols usually have additional layer between transport layer and application layer, and they incur additional costs because of encrypting all the traffic transmitted. This results in unnecessary performance degradation because it also encrypts data that does not require confidentiality. In this paper, we propose TCP OENC(Optional Encryption) which enables users of the application layer to optionally encrypt only confidential data. TCP OENC operates by TCP option to allow the application layer to encrypt the TCP stream transmitted only on demand. And it ensures transparency between the TCP layer and the application layer. To verify this, we verified that TCP OENC optionally encrypts the stream of TCP session on the embedded board. And then analyzed the performance of the encrypted stream by measuring the elapsed time.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.85-92
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• 2010

There is an authentication method for participants with an encrypted ID and password as a symmetric-key in multilateral video conferencing. It is hard to manage when the security-keys makes many while the transportation processing for the encryption and decryption get complicated when the video conferencing involves a number of participants and the third party as an attackers to gain unauthorized symmetric-key to access video conference which makes a problem less secrecy. This study suggests three ways to enhance security in video conference: first, we present PKI-based X.509 certificate for authenticating the participants of multilateral conferencing and we suggest to encode and decode the video conference media data using a secrecy key created by each of the conference participants; second, a more secured multilateral video conferencing can be expected in a group communication by using the participants secrecy key in creating and distributing group keys, where the group key will be renewed whenever there is change in the group member; and finally, we suggest to encode the RTP payload of the media data before transmission.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2014-2020
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• 2016

In general, automatic access control management system using smart door-lock must be always exposed to security vulnerability during wireless communication based on Bluetooth. In particular, important information such as a secrete key can be exposed to the attacker when the authentication protocol has been operating in the wireless section. Therefore important information exchanged in the radio section needs to be properly encrypted. In order to analyze security vulnerability for automatic access control management system of public facilities such as subway vent, GNU Radio platform and HackRF device will be considered and experimented. Proposed experimental system to perform software based power analysis attack could be very effectively applied. As a result, important information such as packet type, CRC, length of data, and data value can be easily decoded from wireless packet obtained from HackRF device on GNU Radio platform. Constructed experimental system will be applied to avoid some security problems.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.11
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• pp.351-356
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• 2020

With the spread of COVID-19 infections, the need for next-generation learning management system for undact education is rapidly increasing, and the Ministry of Education is planning future education through the establishment of fourth-generation NEIS. If the fourth-generation NEIS System is well utilized, there are advantages such as providing personalized education services and activating the use of educational data, but a solution to the illegal access problem in an access control environment where strict authorization is difficult due to various user rights. In this paper, we propose a blockchain-based access control audit system for next-generation learning management. Sensitive personal information is encrypted and stored using the proposed system, and when the auditor performs an audit later, a secret key for decryption is issued to ensure auditing. In addition, in order to prevent modification and deletion of stored log information, log information was stored in the blockchain to ensure stability. In this paper, a hierarchical ID-based encryption and a private blockchain are used so that higher-level institutions such as the Ministry of Education can hierarchically manage the access rights of each institution.

• The KIPS Transactions:PartD
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• v.9D no.3
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• pp.477-486
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• 2002

vCard that is the electronic business card automates the exchange of personal information typically found on a traditional business card. vCard information contains not only simple text, but also graphics and multimedia data like pictures, company logos, Web addresses, and so on. This paper describes the design and implementation of Web-based vCard agent system for exchanging vCard, an electronic business card and searching another user's vCard in mobile phone environment. In today's business environment, such as that this information is typically exchanged on business cards. Our web agent system in this paper connect web server which provide vCard service and search, edit vCard information displayed by web browser of mobile phone and exchange vCard with another user through internet. Considering characteristics of wireless devices that have limited storage space, It also saves constructed XML documents that include user's informations in a web server and solves the security problem by exchanging not personal data or XML but encrypted directory name where XML document exits as exchanging vcard.

• Convergence Security Journal
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• v.21 no.1
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• pp.3-7
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• 2021

In quantum cryptographic communication based on quantum mechanics, each piece of information is loaded onto individual photons and transmitted. Therefore, it is impossible to eavesdrop on only a part, and even if an intruder illegally intercepts a photon and retransmits it to the recipient, it is impossible to send the same information to the photon by the principle of quantum duplication impossible. With the explosive increase of various network-based services, the security of the service is required to be guaranteed, and the establishment of a quantum cryptographic communication network and related services are being promoted in various forms. However, apart from the development of Quantum Key Distribution (QKD) technology, a lot of research is needed on how to provide network-level services using this. In this paper, based on the quantum encryption device, we propose an integrated data structure for transferring quantum keys between various quantum encryption communication network devices and realizing an encrypted transmission environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.729-738
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• 2019

In this paper, we propose two-way authentication protocol between unmanned systems in tactical wireless networks in which long distance communications are not guaranteed due to a poor channel conditions. It is assumed that every unmanned systems have same random data set before they put into combat. The proposed protocol generates authentication code(AC) using random data that causes hash collision. The requester for authentication encrypts the materials such as their identifier, time-stamp, authentication code with the secret key. After then the requester transmits the encrypted message to the receiver. The receiver authenticates the requester by verifying the authentication code included in the request message. The performance analysis of the proposed protocol shows that it guarantees the security for various attack scenarios and efficiency in terms of communication overhead and computational cost. Furthermore, we analyzed the effect of the parameter values of the proposed protocol on the performance and suggest appropriate parameter value selection guide according to the level of security requirement.

• Convergence Security Journal
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• v.17 no.5
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• pp.101-110
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• 2017

The purpose of this study is to examine possibilities of industry secret information leakage through IoT devices and to prevent information leakage from the perspective of administrative and technique security. From the administrative security perspective, first, it is important to face the possibility of industry information data leakage through anyone who can access companies and should establish guidelines to limit the use of IoT devices when entering companies. Second, security management guideline should be prepared by companies or upon user's request and use of any electronic devices sharing wireless internet connection should be eliminated or restricted. From technique security perspective, channels that sharing IoT devices in computers should be controlled since industry secret information are stored in computers and servers. Furthermore, IoT devices that accessing wireless internet network or devices that already registered should be regularly checked in order to minimize any information leakage. Lastly, data and information stored in computers and servers should be encrypted.