• Journal of KIISE:Information Networking
• /
• v.32 no.1
• /
• pp.1-11
• /
• 2005

Internet has become an essential part of our daily lives. Many of the day to day activities can already be carried out over Internet, and its convenience has greatly increased the number of Internet users. Hut as Internet gains its popularity, the illicit incidents over Internet has also proliferated. The intruder trace-back technology is the one that enables real time tracking the position of the hacker who attempts to invade the system through the various bypass routes. In this paper, the RTS algorithm which is the TCP connection trace-back system using the watermarking technology on Internet is proposed. Furthermore, the trace-bark elements are modeled by analyzing the Proposed trace-back algorithm, and the results of the simulation under the virtual topology network using ns-2, the network simulation tool are presented.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.1
• /
• pp.28-34
• /
• 2008

Biofilm formation in association with the intercellular adhesion (icaADBC) gene cluster is a serious problem in nosocomial infections of Staphylococcus aureus. In all 112 S. aureus strains tested, the ica genes were present, and none of these strains formed biofilms. The biofilm formation is known to be changeable by environmental factors. We have found about 30% of phase variation in these strains with treatment of tetracycline, pristinamycin, and natrium chloride. However, this phenotype disappeared without these substances. Therefore, we have constructed stable biofilm-producing variants through a passage culture method. To explain the mechanism of this variation, nucleotide changes of ica genes were tested in strain S. aureus 483 and the biofilm-producing variants. No differences of DNA sequence in ica genes were found between the strains. Additionally, molecular analysis of three regulatory genes, the accessory gene regulator (agr) and the staphylococcal accessory regulator (sarA), and in addition, alternative transcription factor ${\sigma}^B$ (sigB), was performed. The data of Northern blot and complementation showed that SigB plays an important role for this biofilm variation in S. aureus 483 and the biofilm-producing variants. Sequence analysis of the sigB operon indicated three point mutations in the rsbU gene, especially in the stop codon, and two point mutations in the rsbW gene. This study shows that this variation of biofilm formation in S. aureus is deduced by the role of sigB, not agr and sarA.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.2 s.46
• /
• pp.171-180
• /
• 2007

The financial crime that used morale anger Phishing, Pharming, Vishing, SMiSing etc. will gain during recent cyber crimes. We are study systematically whether or not leakage of information and infringement can how easily occur to Phishing, Vishing, SMiSing using a social engineering technique and VoIP at these papers through experiment. A hacker makes Phishing, Vishing site, and test an information infringement process of a user through PiSing mail and a virus, a nasty code, Vishing, a SMiSing character, disarmament of Keylogger prevention S/W etc. as establish server. Information by Phishing, Vishing, SMiSing is infringed with leakage in the experiment results, and confirm, and test certified certificate and White List and a certified authentication mark, plug-in program installation etc. to prevention, and security becomes, and demonstrate. Technical experiment and prevention regarding Phishing of this paper and Vishing attack reduce the damage of information infringement, and be education for Ubiquitous information security will contribute in technical development.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.4
• /
• pp.239-248
• /
• 2007

There's been a difficulty for general corporate to adopt recent incident response study because those studies focus on nation wide CERT Coordination Center or large organization aspect. This study is focus on study and design on security ticket based CERT system through analysis Security management's threat element, attack element, response element and it also help general corporate establish incident response process that is adjusted on IT operation. Confirmed CERT model's effectiveness and effect of quantitative Security incident management way that propose executing Security incident response experiment on the basis of this way. This study which provides general corporate oriented CERT model can be used to improve corporate's capability of responding incident by quantified management technique and select incident response SLA indicator. Already, formation which operate CERT can heighten corporation's information protection level by measure Security incident response result as metrical and analyze and improve problem continuously.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.5B
• /
• pp.381-387
• /
• 2003

The importance of protection for data and information is increasing by the rapid development of information communication and network. And concern of the private-information protection is increasing for the requested user's demand. Analysis of unknown signal characteristics is importance for the safe system maintenance from hacker and cracker. Detected target of unknown signals is virus, inner invader and outer invader, etc. Because existed unknown signal detection method exist individually for the virus, inner invader and outer invader system performance is very lower and system cost is very much. Therefore, in this paper proposed merging IDS system performs detection for virus, inner intrusion and outer intrusion method. Design of the proposed system is used Synopsys Ver. 1999.10 and VHDL coding. The proposed IDS system is practical in the system performance and cost for the individually existed IDS, and proposed IDS system utilized a part of system resources.

• Journal of the Korea Society of Computer and Information
• /
• v.11 no.5 s.43
• /
• pp.241-250
• /
• 2006

Regarding a spam attack and the interception that a spinoff is largest among weakness of VoIP service at these papers study. Write scenario of a spam attack regarding VoIP service, and execute Call spam, Instant Messaging spam, Presence spam attack. A spam attack is succeeded in laboratories, and prove, and confirm damage fact of a user in proposals of a spam interception way of VoIP service, 1) INVITE Request Flood Attack 2) Black/White list, 3) Traceback, 4) Black Hole-Sink Hole, 5) Content Filtering, 6) Consent based Communication, 7) Call act pattern investigation, 8) Reputation System Propose, and prove. Test each interception plan proposed in VoIP networks, and confirm security level of a spam interception. Information protection of VoIP service is enlarged at WiBro, BcN, and to realize Ubiquitous Security through result of research of this paper contribute, and may make.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.6
• /
• pp.217-224
• /
• 2008

EThis paper is study regarding banking institution and DoS attack regarding government organization which occurred in 2008. We used a tool aggressive actual DoS You install the N-IDS which used Snort in networks in order to detect a DoS attack. Storages of Winpcap and a packet to detect a packet and MySQL, HSC, to analyze. We install NET Framework etc. E-Watch etc. analyzes Packet regarding a DoS attack of a hacker and TCP, UDP etc. information, Port, MAC and IP information etc. through packet analysis tools. There is a meaning you analyze data regarding the cyber DoS, DDoS attack that is dysfunction of Ubiquitous Information Society, and it generates forensics data regarding an invader and back-tracking analysis data, and to ensure safe Internet information system through this paper study.

• Journal of Convergence Society for SMB
• /
• v.5 no.2
• /
• pp.1-6
• /
• 2015

Small and medium-sized companies lack countermeasures to secure the safety of a information system. In this circumstance, they have difficulties regarding the damage to their images and legal losses, when the information is leaked. This paper examines the information leakage of the system and hacking methods including APT attacks. Especially, APT attack, Advanced Persistent Threats, means that a hacker sneaks into a target and has a latency period of time and skims all the information related to the target, and acts in the backstage and neutralize the security services without leaving traces. Because he attacks the target covering up his traces not to reveal them, the victim remains unnoticed, which increases the damage. This study examines attack methods and the process of them and seeks a countermeasure.

• The Journal of Society for e-Business Studies
• /
• v.16 no.4
• /
• pp.75-85
• /
• 2011

Although progress in information technology has made our life prosperous. But it accompanied a number of adverse effects in various aspects. Especially, internet according to the increasing requirements for privacy and security, IP concealment network technologies to ensure the anonymity are constantly being developed. IP concealment network technologies is aiding the user to bypass the blocked sites can be used to access for information gathering, and they could be used for a malicious hacker to hide his attacks. However, due to complex routing path, local communication bandwidth sangyiham, and internode encryption there are also disadvantages that communication speed is significantly less. In this paper, the research for improving the performance of anonymous networks is to proceed by the communication speed measurement that using GeoIP the particular country with high-bandwidth is Specified or path length is limited.

• Journal of Korea Game Society
• /
• v.11 no.6
• /
• pp.81-93
• /
• 2011

Identity theft happens frequently in popular MMORPG(Massively Multi-player Online Role Playing Games) where profits can be gained easily. In spite of the importance of security about identity theft in MMORPG, few methods to prevent and detect identity theft in online games have been proposed. In this study, we investigate real identity theft cases of an online game and define the representative patterns of identity theft as the speedy type, cautious type, and bold type. We then propose the automatic identity theft detection model based on the multi-class classification. We verify the system with one of the leading online games in Korea. The multi-class detection model outperforms the existing binary-class one(hacked or not).