• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.743-755
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• 2013

In recent years, the malicious apps with malicious code in normal apps are increasingly redistributed in Android market, which may incur various problems such as the leakage of authentication information and transaction information and fraudulent transactions when banking apps to process the financial transactions are exposed to such attacks. Thus the financial authorities established the laws and regulations as an countermeasures against those problems and domestic banks provide the integrity verification functions in their banking apps, yet its reliability has not been verified because the studies of the safety of the corresponding functions have seldom been conducted. Thus this study suggests the vulnerabilities of the integrity verification functions of banking apps by using Android reverse engineering analysis techniques. In case the suggested vulnerabilities are exploited, the integrity verification functions of banking apps are likely to be bypassed, which will facilitate malicious code inserting attacks through repackaging and its risk is very high as proved in a test of this study. Furthermore this study suggests the specific solutions to those vulnerabilities, which will contribute to improving the security level of smartphone financial transaction environment against the application forgery attacks.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.33-40
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• 2021

Automatic Speech Recognition(ASR) is a technology that analyzes human speech sound into speech signals and then automatically converts them into character strings that can be understandable by human. Speech recognition technology has evolved from the basic level of recognizing a single word to the advanced level of recognizing sentences consisting of multiple words. In real-time voice conversation, the high recognition rate improves the convenience of natural information delivery and expands the scope of voice-based applications. On the other hand, with the active application of speech recognition technology, concerns about related cyber attacks and threats are also increasing. According to the existing studies, researches on the technology development itself, such as the design of the Automatic Speaker Verification(ASV) technique and improvement of accuracy, are being actively conducted. However, there are not many analysis studies of attacks and threats in depth and variety. In this study, we propose a cyber attack model that bypasses voice authentication by simply manipulating voice frequency and voice speed for AI voice recognition service equipped with automated identification technology and analyze cyber threats by conducting extensive experiments on the automated identification system of commercial smartphones. Through this, we intend to inform the seriousness of the related cyber threats and raise interests in research on effective countermeasures.

• Korean journal of communication and information
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• v.45
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• pp.296-340
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• 2009

The power of media has always been problematic in the countries of full press freedom. Originally, the media used to be an effective vehicle for communication within human beings. However, it exerts an overwhelming power toward human society. Through applying the well-known four dog models in terms of media function, this study attempts to examine how the press media in South Korea transformed themselves into another powerful independent organization or institution after regime shift in 1987. The whole editorials of four sampled newspapers were analyzed through frame analysis model. The ChosunIlbo, known as a conservative and pro-government paper, shows to take the role of supporting chaebol policies under Roh TaeWoo Administration. However, it criticizing sharply against the chaebol policies of Roh MooHyun Administration. The JoongangIlbo, known as a pro-chaebol paper, appears anti-government position through the entire four administrations in terms of chaebol policies. Particularly, it reveals hostile editorial coverage during the Roh MooHyun Administration. However, KyunghyangShinmun, currently known as a liberal paper, viewed somewhat complicated positions (see text in more detail) because of its ownership turbulence during the past twenty years. On the other hand, Hangyoreh, regarded as a progressive paper, keeps in supportive attitude consistently against the four sampled administrations as far as regulating each government policies for chaebols.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.15-26
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• 2011

The development of IT technology and information communication networks activated to online financial transactions; the users were able to get a variety of financial services. However, unlike the positive effect that occurred on 7 July 2009 DDoS(Distribute Denial of Service) attacks, such as damaging to the user, which was caused negative effects. Authentication technology(OTP) is used to online financial transaction, which should be reviewed to safety with various points because the unpredictable attacks can bypass the authentication procedure such as phishing sites, which is occurred. Thus, this paper proposes mobile OTP(One Time Password) Mechanism, which is based on PKI to improve the safety of OTP authentication. The proposed Mechanism is operated based on PKI; the secret is transmitted safely through signatures and public key encryption of the user and the authentication server. The users do not input in the web site, but the generated OTP is directly transmitted to the authentication server. Therefore, it is improvement of the availability of the user and the resolved problem is exposed from the citibank phishing site(USA) in 2006.

• Journal of Industrial Convergence
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• v.21 no.9
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• pp.41-48
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• 2023

Recently, there has been a sharp increase in the damages caused by ransomware across various sectors of society, including individuals, businesses, and nations. Ransomware is a malicious software that infiltrates user computer systems, encrypts important files, and demands a ransom in exchange for restoring access to the files. Due to its diverse and sophisticated attack techniques, ransomware is more challenging to detect than other types of malware, and its impact is significant. Therefore, there is a critical need for accurate detection and mitigation methods. To achieve precise ransomware detection, an inference engine of a detection system must possess knowledge of ransomware features. In this paper, we propose a model to extract and classify the characteristics of ransomware for accurate detection of ransomware, calculate the similarity of the extracted characteristics, reduce the dimension of the characteristics, group the reduced characteristics, and classify the characteristics of ransomware into attack tools, inflow paths, installation files, command and control, executable files, acquisition rights, circumvention techniques, collected information, leakage techniques, and state changes of the target system. The classified characteristics were applied to the existing ransomware to prove the validity of the classification, and later, if the inference engine learned using this classification technique is installed in the detection system, most of the newly emerging and variant ransomware can be detected.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.251-258
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• 2012

The conventional network security solutions for manufacturing or factory automation devices are concentrated on protecting the internal networks from the attacks of external networks. Recently, however, so called Day-zero attacks are increased; the threat from internal devices such as notebooks, USB devices are as critical as attacks from external networks. Thus a new security solution is needed to protect manufacturing devices from both external and internal threat. To this purpose, we propose an edge-security system to provide cost effective, integrated, and simple end-point security solution specialized for automated manufacturing devices, which may avoid the shortcomings of NAC.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.805-816
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• 2017

Tor is a popular, low-latency open network that offers online anonymity to users by concealing their information from anyone conducting traffic analysis. At the same time, a number of conventional passive and active attacking schemes have been proposed to compromise the anonymity provided by the Tor network. In addition to attacks on the network through traffic analysis, interacting with an unsecured application can reveal a Tor user's IP address. Specific traffic from such applications bypasses Tor proxy settings in the user's machine and forms connections outside the Tor network. This paper presents such applications and shows how they can be used to deanonymize Tor users. Extensive test studies performed in the paper show that applications such as Flash and BitTorrent can reveal the IP addresses of Tor users.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.17-30
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• 2015

Unlike existing widely used bytecode-centric Android application code obfuscation methodology, our scheme in this paper makes encrypted file i.e. DEX file self-extracted arbitrary Android application. And then suggests a method regarding making the loader app to execute encrypted file's code after saving the file in arbitrary folder. Encrypted DEX file in the loader app includes original code and some of Manifest information to conceal event treatment information. Loader app's Manifest has original app's Manifest information except included information at encrypted DEX. Using our scheme, an attacker can make malicious code including obfuscated code to avoid anti-virus software at first. Secondly, Software developer can make an application with hidden main algorithm to protect copyright using suggestion technology. We implement prototype in Android 4.4.2(Kitkat) and check obfuscation capacity of malicious code at VirusTotal to show effectiveness.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.1
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• pp.69-79
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• 2013

Recently, many enterprises are suffering from advanced types of malware and their variants including intelligent malware that can evade the current security systems. This addresses the fact that current security systems have limits on protecting advanced and intelligent security threats. To enhance the overall level of security, first of all, it needs to increase detection ratio of each security solution within a security system. In addition, it is also necessary to implement internetworking between multiple security solutions to increase detection ratio and response speed. In this paper, we suggest a collaborative security response method to overcome the limitations of the previous Internet service security solutions. The proposed method can show an enhanced result to respond to intelligent security threats.

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