• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1267-1277
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• 2021

The phone number used for advertising messages and voices used as bait in the voice phishing crime access stage is being used to send out a large amount of illegal loan spam, so we want to quickly block it. In this paper, our system is designed to block the usage of the phone number by rapidly restricting the use of the voice spam phone number that conducts illegal loan spam and voice phishing, and at the same time sends continuous calls to the phone number to prevent smooth phone call connection. The proposed system is a representative collaboration model between an illegal spam reporting agency and an investigation agency. As a result of developing the system and applying it in practice, the number of reports of illegal loaned voice spam and text spam decreased by 1/3, respectively. We can prove the effectiveness of this system by confirming that.

• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.75-87
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• 2007

As the VoIP service quality is getting better and many shortcomings are being overcome, users are getting interested in this service. Also, there are several additional features that provide a convenience to users such as presence service, instant messaging service and so on. But, as there are always two sides of rein, some security issues have users hesitate to make use of it. This paper deals with one of the issues, the VoIP spam problem. We took into account the signal pattern of voice message in spam call and we have constructed voice signal models of normal call, normal call with noise and spam call. Each voice signal case is inserted into our spam decision algorithm which detects the spam calls based on the amount of information in the call signal. We made use of the DEVS-$Java^{TM}$ for our modeling and simulation. The contribution of this work is in suggestion of a way to detect voice spam call signal and testing of the method using modeling and simulation methodology.

• Journal of Industrial Convergence
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• v.19 no.6
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• pp.37-47
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• 2021

Today, people share information and communicate with others using various information and communication media such as e-mail, smartphones, SNS, etc. However, it is being used in malicious attacks to send a large amount of illegal spam or to use it for fraud by using illegally collected personal information and devices that are vulnerable to security. Illegal spam, smishing, and fraudulent mail(SCAM) cause a lot of direct and indirect damage to companies and users, including not only social costs such as mental fatigue, but also unnecessary consumption of IT infrastructure resources and economic losses. Although there are regulations related to spam, violators of the law are still on the rise by circumventing the law, and victims are constantly occurring, so it is necessary to review what the problem is. This study examined domestic and foreign spam-related regulations and spam-related response activities, identified problems, and suggested improvement countermeasures. Through this study, it was intended to suggest directions for improving spam-related systems in order to block illegal spam and prevent fraudulent damage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.670-676
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• 2008

There is a difficult plane letting a security threat to occur in Internet networks as VoIP service uses technology-based the Internet is inherent, and you protect without adjustment of the existing security solution or changes with real-time service characteristics. It is a voice to single networks The occurrence security threat that it is possible is inherent in IP networks that effort and cost to protect a data network only are complicated relatively as provide service integrated data. This paper about various response way fields to be able to prevent analysis regarding definition regarding VoIP spam and VoIP spam technology and VoIP spam.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.203-206
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• 2017

최근 휴대전화 문자스팸 차단 강화로 인한 풍선효과로 휴대전화 음성스팸이 지속적으로 증가하고 있고, 2015년 3월부터는 음성스팸 건수가 문자스팸 건수를 역전해서 급속도로 증가하고 있어 효율적으로 음성스팸을 차단할 수 있는 시스템 구축의 필요성이 대두되고 있다. 이에, 음성스팸 신고번호와 음성스팸 가상 트랩(실제 존재하지 않는 가상의 휴대전화번호를 적용)을 통해 탐지된 내용을 기반으로 음성스팸 전화번호 차단리스트를 생성하고 이를 이통사에게 제공하여 일정기간 동안 음성호를 차단하는 음성스팸 실시간 차단시스템을 설계하고자 한다.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.3
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• pp.261-265
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• 2008

As increasing the user of VoIP service using ITSP(Internet Telephony Service Provider), the VoIP spam becomes a big problem. The spam used in the existing public telephone is detected by using the pattern inspection of call behavior because it is difficult to filter contents for the characteristic of real-time voice communication. However there is a false-positive problem. The threat on spam remains where spam with low threshold can't be detected or users share one number. In this paper, we propose anti-spam for VoIP based on luring test. The proposed method gives a user luring test and he/she can connect to a receiver if passing turing test. A ticket is given to a user that pass luring test and it reduces overhead of luring test in re-dial. The proposed method is implemented on ASUS WL-500G wireless router and Asterisk IP-PBX. Experimental results show the effectiveness of the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.908-913
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• 2009

Mobile phones became important household appliance that cannot be without in our daily lives. And the short messaging service (SMS) in these mobile phones is 1.5 to 2 times more than the voice service. However, the spam filtering functions installed in mobile phones take a method to receive specific number patterns or words and recognize spam messages when those numbers or words are present. However, this method cannot properly filters various types of spam messages currently dispatched. This paper proposes a more powerful and more adaptive spam filtering system using SVM and thesaurus. The system went through a process of isolating words from sample data through pro-processing device and integrating meanings of isolated words using a thesaurus. Then it generated characteristics of integrated words through the chi-square statistics and studied the characteristics. The proposed system is realized in a Window environment and the performance is confirmed through experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.237-240
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• 2011

Voice over Internet Protocol calls using administrative agency to build a national information and communication service, 'C' group, providers, the KT, SK Broadband, LG U+, Samsung SDS, as there are four operators. To prepare for an attack on Voice over Internet Protocol for administrative agency, security is a need for research to support the model. In this paper, the Internet telephone business of Administrative Agency to investigate and analyze the specific security measures to respond. Should set priorities around confidentiality about five security threats from NIS to Study of Voice over Internet Protocol Security Response Model for Administrative Agency. (1) Illegal wiretapping, (2) call interception, (3) service misuse, (4) denial of service attacks, (5) spam attacks, write about and analyze attack scenarios. In this paper, an analysis of protection by security threats and security breaches through a step-by-step system to address the research study is a step-by-step development of the corresponding model.

• Journal of the Korea Convergence Society
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• v.3 no.3
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• pp.7-12
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• 2012

mVoIP (mobile Voice over Internet Protocol) service is a technology to transmit voice data through an IP network using mobile device. mVoIP provides various supplementary services with low communication cost. It can maximize the availability and efficiency by using IP-based network resources. In addition, the users can use voice call service at any time and in any place, as long as they can access the Internet on mobile device easily. However, SIP on mobile device is exposed to IP-based attacks and threats. Observed cyber threats to SIP services include wiretapping, denial of service, and service misuse, VoIP spam which are also applicable to existing IP-based networks. These attacks are also applicable to SIP and continuously cause problems. In this study, we analysis the threat and vulnerability on mVoIP service and propose several possible attack scenarios on existing mobile VoIP devices. Based on a proposed analysis and vulnerability test mechanism, we can construct more enhanced SIP security mechanism and stable mobile VoIP service framework after eliminating its vulnerability on mobile telephony system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.265-268
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• 2011

Voice over Internet protocol(VoIP) is support a VoIP service as All-IP method and Gateway method etc. All-IP method to the unit in an Internet environment by applying both the IP service is an VoIP system. Gateway method, using a normal phone call in a way that the Internet is using VoIP. In this paper, scanning and analyze the vulnerability for VoIP systems and networks from All-IP method and the Gateway method In the test bed. All-IP method and Gateway method found in the VoIP vulnerabilities, hacking attack, a denial of service attacks and VoIP spam attacks are carried out. Through analysis of post-attack security measures is proposed.