• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.5
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• pp.81-88
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• 2010

Sun et al. proposed a new design of wearable token system for security of mobile devices, such as a notebook and PDA. In this paper, we show that Sun et al.'s system is vulnerable to off-line password guessing attack and man in the middle attack based on known plain-text attack. We propose an improved scheme which overcomes the weaknesses of Sun et al.'s system. The proposed protocol requires to perform one modular multiplication in the wearable token, which has low computation ability, and modular exponentiation in the mobile devices, which have sufficient computing resources. Our protocol has no security problem, which threatens Sun's system, and known vulnerabilities. That is, the proposed protocol overcomes the security problems of Sun's system with minimal overheads.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1735-1742
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• 2011

Now a days, as a mass-storage USB becomes comfortable to carry, function of USB is being developed fast. However, there is a problem that the personal information which is stored in USB could be exposed being used with negative purpose without other certification process. This paper suggests OTP(One-Time Password)-based certification protocol of USB to securely protect personal information stored in USB without additional certification information. The proposed OTP based certification protocol of USB not only demands low calculations but also prevents physical approach of USB of other network and does not allow unnecessary service access of user because it conducts simple action and uses one-way hash function. Therefore, communication overhead and service delay is improved. In the experiment, the proposed protocol compares and evaluates throughput of certification server according to the numbers of USB and delay time of packet certification with a device(USB driver) which simply save device and a device(USB Token) which can calculate by oneself. As a result, it is improved as the number of 12.5% in the certification delay time on average and is improved as the number of 10.8% in the throughput of certification server according to the numbers of USB.

• Journal of the Korean Society for information Management
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• v.19 no.1
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• pp.23-46
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• 2002

With explosively increasing digital contents, library and Information center should have a new role between knowledge providers and knowledge users as information brokering organization. Electronic transaction system should be required for performing this brokering service since economic value is added to information and knowledge in information society. The developments and changes around library are keeping up with increasing building digital library and digitalizing printed sources. With the rapidly changing circumstances, the Internet is currently witnessing an explosive growth. By serving as a virtual information resource. the Internet can dramatically change the way business is conducted and Information is provided. However because of features o( the Internet like openness and information sharing, it has fundamental vulnerabilities in security issues. For Instance, disclosure of private information and line eavesdropping such as password, banking account, transaction data on network and so on are primary obstruction factors to activation of digital contents delivery on network. For high network security and authentication, this paper looks at smart card technologies and proposes multi-authentication protocol based on smart card on open network, implements and analyzes it.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.135-141
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• 2011

Recent advances in mobile devices and development of various mobile applications dealing with private information of users made user authentication in mobile devices a very important issue. This paper presents a new user authentication method based on touch screen interfaces. This method uses for authentication the PIN digits as well as the exact locations the user touches to input these digits. Our method is fully compatible with the regular PIN entry method which uses numeric keypads, and it provides better usability than the behavioral biometric schemes because its PIN registration process is much simpler. According to our experiments, our method guarantees EERs of 12.8%, 8.3%, and 9.3% for 4-digit PINs, 6-digit PINs, and 11-digit cell phone numbers, respectively, under the extremely conservative assumption that all users have the same PIN digits and cell phone numbers. Thus we can guarantee much higher performance in identification functionality by applying this result to a more practical situation where every user uses distinct PIN and sell phone number. Finally, our method is far more secure than the regular PIN entry method, which is verified by our experiments where attackers are required to recover a PIN after observing the PIN entry processes of the regular PIN and our method under the same level of security parameters.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.607-615
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• 2015

Mosts user of internet and smart phone has certificate, and uses it when money transfer, stock trading, on-line shopping, etc. Mosts user stores certificate in a hard disk drive of PC, or the external storage medium. In particular, the certification agencies are encouraged for user to store certificate in external storage media such as USB memory rather than a hard disk drive. User think that the external storage medium is safe, but when it is connect to a PC, certificate may be copied easily, and can be exposed to hackers through malware or pharming site. Moreover, if a hacker knows the user's password, he can use user's certificate without restrictions. In this paper, we suggest secure management scheme of the private key file using a password of the encrypted private key file, and a USB Memory's hardware information. The private key file is protected safely even if the encrypted private key file is copied or exposed by a hacker. Also, if the password of the private key file is exposed, USB Memory's container ID, additional authentication factor keeps the private key file safe. Therefore, suggested scheme can improve the security of the external storage media for certificate.

• Convergence Security Journal
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• v.12 no.1
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• pp.17-25
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• 2012

SQL Injection techniques disclosed web hacking years passed, but these are classified the most dangerous attac ks. Recent web programming data for efficient storage and retrieval using a DBMS is essential. Mainly PHP, JSP, A SP, and scripting language used to interact with the DBMS. In this web environments application does not validate the client's invalid entry may cause abnormal SQL query. These unusual queries to bypass user authentication or da ta that is stored in the database can be exposed. SQL Injection vulnerability environment, an attacker can pass the web-based authentication using username and password and data stored in the database. Measures against SQL Inj ection on has been announced as a number of methods. But if you rely on any one method of many security hole ca n occur. The proposal of four levels leverage is composed with the source code, operational phases, database, server management side and the user input validation. This is a way to apply the measures in terms of why the accident preventive steps for creating a phased step-by-step response nodel, through the process of management measures, if applied, there is the possibility of SQL Injection attacks can be.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.327-333
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• 2009

In 2004, Das et al. proposed a scheme for preserving a user anonymity. However, In 2005, Chien and Chen pointed out that Das et al. scheme fail to protect the user anonymity, and proposed a new scheme. And then in 2007, Hu et al. pointed out that Chien and Chen scheme also has some problems; it is Strong masquerading server/user attack, Restricted replay attack, Denial of service attack. it also slow wrong password detection, and proposed a new scheme. In 2008, Bindu et al. repeatedly pointed out on Chien and Chen scheme and proposed their scheme. However, we point out that all of their scheme also has some problems; it is not to protect the user anonymity and Denial of service attack. In addition, Bindu et al. is vulnerable to Strong masquerading server/user attack. Therefore, we demonstrate that their scheme also have some problems; it is the user anonymity and denial of service attack as above.

• Convergence Security Journal
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• v.13 no.2
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• pp.155-163
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• 2013

Connection hijacking attack using the vulnerability of the TCP protocol to redirect TCP stream goes through your machine actively (Active Attack). The SKEY such as one-time password protection mechanisms that are provided by a ticket-based authentication system such as Kerberos or redirection, the attacker can bypass.Someone TCP connection if you have access on TCP packet sniffer or packet generator is very vulnerable. Sniffer to defend against attacks such as one-time passwords and token-based authentication and user identification scheme has been used. Active protection, but these methods does not sign or encrypt the data stream from sniffing passwords over insecure networks, they are still vulnerable from attacks. For many people, an active attack is very difficult and so I think the threat is low, but here to help break the illusion successful intrusion on the UNIX host, a very aggressive attack is presented. The tools available on the Internet that attempt to exploit this vulnerability, known as the recent theoretical measures is required. In this paper, we propose analysis techniques on a wireless network intruder detection.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.501-507
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• 2015

The online banking service handles a banking business over the internet, it is necessary to ensure that all financial transactions are processed securely. So, there are various authentication technique for e-banking service : a certificate, a personal identification number(PIN), a security card and a one-time password(OTP). Especially, the security card is most important means including secret information. If the secret information of card is leaked, it means not only loss of security but also easy to attack because security card is a difficult method to get. In this paper, we propose that a multi-channel security card saves an secret information in distributed channel. Proposed multi-channel security card reduces vulnerability of the exposed and has a function to prevent phishing attacks through decreasing the amount of information displayed and generating secret number randomly.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.297-302
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• 2015

The increase in applying IT to vehicles has given birth to smart cars or connected cars. As smarts cars become connected with external network systems, threats to communication security are on the rise. With simulation test results supporting such threats to Convergence security in vehicular communication, concerns are raised over relevant vulnerabilities, while an increasing number of studies on secure vehicular communication are published. Hacking attacks against vehicles are more dangerous than other types of hacking attempts because such attacks may threaten drivers' lives and cause social instability. This paper designed a Convergence security protocol for inter-vehicle and intra-vehicle communication using a hash function, nonce, public keys, time stamps and passwords. The proposed protocol was tested with a formal verification tool, Casper/FDR, and found secure and safe against external attacks.