• Review of KIISC
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• v.31 no.5
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• pp.13-19
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• 2021

사이버 공격이 점점 복잡해지고 빠르게 진화하면서, 기존에 알려졌거나 향후 예견되는 위협에 대한 근거를 바탕으로 한 지식인 사이버 위협 인텔리전스(CTI)를 구축하고 공유하려는 노력이 최근 주목을 받고 있다. 특히, Transport Layer Security(TLS)와 같은 암호화 프로토콜을 활용해 암호화된 인터넷 트래픽이 증가하면서 패킷 페이로드(payload)의 분석이 어려워짐에 따라, 암호화된 네트워크 트래픽을 핑거프린팅(fingerprinting)하고 이 정보를 공유해 위협의 근거로 활용하고자 하는 시도들이 등장하고 있다. 본 논문에서는 최근에 제안된 주요 TLS 핑거프린팅 기법 및 이를 사이버 위협 인텔리전스 구축을 위해 데이터베이스화 하는 사례를 소개한다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.3
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• pp.641-653
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• 1999

The paper is design and implementation of the system to support security communication between a Web Browser and a CGI program by a Web Server using PKI(Public Key Infrastructure. This system uses GSS(Generic Security Service)-API to communicate with PKI, offers a Web user a Client Proxy, and offers a CGI developer there library functions related with security. TLS(Transport Layer Security) supports security communication between a Web Browser and a Web Server, but the system supports security communication between a Web Browser and a CGI program as the protected data received from a Client Proxy are sent to a CGI program, and the CGI program decrypts the data using the library functions supported by this system.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.610-612
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• 2002

전송계층에서의 안전한 통신을 위한 Secure Sockets Layer(SSL)와 Transport Layer Security(TLS)의 Handshake 프로토콜에서 Session ID의 저장이 매우 짧은 시간 동안 저장됨으로 전체적인 Full Handshake의 횟수가 증가한다. 따라서, 안전한 Session resume 보장함으로 서버의 session cache 기한을 연장할 수 있으며 전체적인 Full Handshake 프로토콜의 횟수를 줄일 수 있다. 본 논문에서는 Handshake 프로토콜의 성능 개선을 위하여 S/key와 같은 해쉬의 일방향 성질을 이용하는 개선된 Session resume의 방안을 제안한다.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.193-202
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• 2015

The development of the security solutions that can provide a variety of security services is needed urgently. For development of the security solutions, analysis of international standard security technology is the key. In this paper, international organizations' standardization(ISO/IEC JTC1 SC27, ITU-T SG-17, IETF Security Area, etc.) and the current trend of the standard security technology are mainly analyzed. The core of the latest security technology(Application Bridging, DNS-based Authentication, HTTP Authentication, IP Security, Javascript Security, Authentication Technology Next Generation, Managed Incident, Web Authorization Protocol, Security Automation, Transport Layer Security, etc.) is analyzed focusing on 18 working groups of the IETF.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.1
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• pp.145-153
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• 2018

SSL (Secure Socket Layer) and TLS (Transport Layer Security) are widely used protocols for secure and encrypted communication over a computer network. However, there have been reported several security vulnerabilities of SSL/TLS over the years. The vulnerabilities can let an adversary carry out critical attacks on SSL/TLS enabled servers. In this paper, we have developed a system which can periodically scan SSL/TLS vulnerabilities on internal network servers and quickly detects, reports and visualizes the vulnerabilities. We have evaluated the system on working servers of Naver services and analyzed detected vulnerabilities. 816 vulnerabilities are found on 213 internal server domains (4.2 vulnerabilities on average) and most vulnerable servers are not opened to public. However, 46 server domains have old vulnerabilites which were found 2016. We could patch and response to SSL/TLS vulnerabilites of servers by leveraging the proposed system.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.785-788
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• 2016

최근 IoT 프로토콜 가운데 가장 활발히 논의되는 프로토콜로 CoAP(Constrained Application Protocol)이 있다. CoAP은 4가지 보안모드로 운영된다. 그 중 3가지 모드인 PresharedKey, RawPublicKey, Certificate 모드의 경우 DTLS(Datagram Transport Layer Security)가 적용된 방식이다. 반면 NoSec 모드는 DTLS가 적용되지 않은 기본방식이다. 본 논문에서는 DTLS의 복잡한 Handshake 방식으로 인한 전력소모 및 Performance의 저하를 고려한 새로운 방식을 제안한다. NoSec 환경의 CoAP 프로토콜에 S-Broker(Secure-Broker)를 적용한 security 및 performance 향상 방안이다. 제안한 방식으로 경량화 통신을 구현하여 무결성과 보안 강도를 높였다. 추가적으로 Proxy의 forwarding 기능과 caching 기능을 구현하여 성능의 향상을 도모한다.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.170-178
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• 2024

Through the growth of the fifth-generation networks and artificial intelligence technologies, new threats and challenges have appeared to wireless communication system, especially in cybersecurity. And IoT networks are gradually attractive stages for introduction of DDoS attacks due to integral frailer security and resource-constrained nature of IoT devices. This paper emphases on detecting DDoS attack in wireless networks by categorizing inward network packets on the transport layer as either "abnormal" or "normal" using the integration of machine learning algorithms knowledge-based system. In this paper, deep learning algorithms and CNN were autonomously trained for mitigating DDoS attacks. This paper lays importance on misuse based DDOS attacks which comprise TCP SYN-Flood and ICMP flood. The researcher uses CICIDS2017 and NSL-KDD dataset in training and testing the algorithms (model) while the experimentation phase. accuracy score is used to measure the classification performance of the four algorithms. the results display that the 99.93 performance is recorded.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.3 no.2
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• pp.81-89
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• 2004

In this paper, we describe ubiquitous environments and the trend of convergence that is an evolution path of. current telecommunication, and show the concept of broadband convergence network, service feature and evolution path. In order to converge wire and wireless communication, telecommunication and broadcasting, voice and data efficiently, broadband convergence network divides a network into service layer, control layer, transport layer, ubiquitous access and terminal layer. Broadband convergence network will be a network that can provide and control broadband multimedia services with QoS and security of different and customized level. Then we depict characteristics and types of broadband multimedia service, and describe the characteristic of broadband convergence network. Finally, we show ubiquitous network based on the broadband convert- gence network to provide ubiquitous service which is a future telecommunication service. We also describe requirements of ubiquitous network such as an intelligent and context based platform, convergence terminals, ubi- quitous computing devices, etc.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.972-974
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• 2016

최근 전 세계적으로 IoT(Internet of Things) 기술이 활발히 연구되고 있다. IoT 환경은 임베디드나 센서 등의 시스템에 적용되는 경우가 많다. 그 특성으로 인해, 적용된 장치들은 경량화되기 때문에 통신을 위한 프로토콜로 UDP 기반 프로토콜을 많이 사용한다. UDP 기반 프로토콜은 TCP 기반 프로토콜보다 보안 기능이 미비하므로 UDP 상에서도 보안 기능을 제공해 줄 수 있는 DTLS(Datagram Transport Layer Security)가 권고된다. 하지만 DTLS는 저전력 IoT 환경을 고려하여 만들어진 프로토콜이 아니다. 그래서 저전력 IoT 환경에서 사용하기에는 힘들다. 하지만 HIGHT(HIGh security and light weigHT) 알고리즘을 사용하면 보안적인 측면을 고려하면서도 DTLS의 알고리즘인 AES(Advanced Encryption Standard)의 높은 에너지 소모량이 해결된다. 본 논문에서는 보안 측면을 고려하면서 에너지 효율까지 고려한 KISA(Korea Internet & Security Agency, 한국인터넷진흥원)의 HIGHT 암호화 알고리즘을 기반으로 DTLS를 경량화하여 저전력 기기에서 적용할 수 있는 방안을 제안한다.

• Convergence Security Journal
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• v.20 no.5
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• pp.11-17
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• 2020

With the increase in cases of using Bluetooth devices used in the electric vehicle charging systems, security issues are also raised. Although various technical efforts have beed made to enhance security of bluetooth technology, various attack methods exist. In this paper, we propose an intelligent Bluetooth intrusion detection system based on a well-known machine learning method, Hidden Markov Model, for the purpose of detecting intelligently representative Bluetooth attack methods. The proposed approach combines packet types of H4, which is bluetooth transport layer protocol, and the transport directions of the packet firstly to represent the behavior of current traffic, and uses the temporal deployment of these combined types as the final input features for detecting attacks in real time as well as accurate detection. We construct the experimental environment for the data acquisition and analysis the performance of the proposed system against obtained data set.