• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.91-104
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• 2003

A masquerader is someone who pretends to be another user while invading the target user's accounts, directories, or files. The masquerade attack is the most serious computer misuse. Because, in most cases, after securing the other's password, the masquerader enters the computer system. The system such as IDS could not detect or response to the masquerader. The masquerade detection is the effort to find the masquerader automatically. This system will detect the activities of a masquerader by determining that user's activities violate a profile developed for that user with his audit data. From 1988, there are many efforts on this topic, but the success of the offers was limited and the performance was unsatisfactory. In this report we propose efficient masquerade detection system using SVM which create the user profile.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.6
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• pp.99-119
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• 2007

The USB flash drive is common used for portable storage. That is able to store large data and transfer data quickly and carry simply. But when you lose your USB flash drive without any security function in use, all stored data will be exposed. So the new USB flash drive supported security function was invented to compensate for the problem. In this paper, we analyze vulnerability of 6 control access program for secure USB flash drives. And we show that exposed password on communication between secure USB flash drive and PC. Also we show the vulnerability of misapplication for initialization. Further we develop a protection profile for secure USB flash drive based on the common criteria version 3.1. Finally, we examine possible threat of 6 secure USB flash drives and supports of security objectives which derived from protection profile.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.1
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• pp.11-21
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• 2008

Biometrics-based user authentication has several advantages over traditional password-based systems for standalone authentication applications. This is also true for new authentication architectures known as crypto-biometric systems, where cryptography and biometrics are merged to achieve high security and user convenience at the same time. Recently, a cryptographic construct, called fuzzy vault, has been proposed for crypto-biometric systems. This construct aims to secure critical data(e.g., secret key) with the fingerprint data in a way that only the authorized user can access the secret by providing the valid fingerprint, and some implementations results for fingerprint have been reported. However, the previous results had some limitation of the provided security due to the limited numbers of chaff data fer hiding real fingerprint data. In this paper, we propose an approach to provide both the automatic alignment of fingerprint data and higher security by using a 3D geometric hash table. Based on the experimental results, we confirm that the proposed approach of using the 3D geometric hash table with the idea of the fuzzy vault can perform the fingerprint verification securely even with more chaff data included.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.4
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• pp.167-174
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• 2008

As both a digital camera and a digital camcorder are popularized in recent years, UCC created by general users is also popularized. Unfortunately, according to that, the lack of privacy is also increasing more and more. The UCC is saved on the recordable media(Media) like DVD and deposited personally as well as distributed through Internet portal service. If you use Internet portal service to put up your contents, you can partially prevent the violation of privacy using security technologies such as authentication and illegal copy protection offered by internet portal service providers. Media also has technologies to control illegal copy. However, it is difficult to protect your privacy if your Media having personal contents is stolen or lost. Therefore, it is necessary to develope an additional security mechanism to guarantee privacy protection when you use Media. In this paper, we describe AACS framework for Media Security and propose improved AACS framework to control the access to personal contents saved on Media.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.1
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• pp.3-11
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• 2009

Forward secrecy in an e-mail system means that the compromising of the long-term secret keys of the mail users and mail servers does not affect the confidentiality of the previous e-mail messages. Previous forward-secure e-mail protocols used the certified public keys of the users and thus needed PKI(Public Key Infrastructure). In this paper, we propose a password-based authenticated e-mail protocol providing forward secrecy. The proposed protocol does not require certified public keys and is sufficiently efficient to be executed on resource-restricted mobile devices.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.3
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• pp.73-82
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• 2009

This paper proposes an efficient and secure user authentication and key agreement scheme instead of the HTTP digest and TLS between the SIP UA and server. Although a number of security schemes for authentication and key exchange in SIP network are proposed, they still suffer from heavy computation overhead on the UA's side. The proposed scheme uses the HTIP Digest authentication and employs the Diffie-Hellman algorithm to protect user password against dictionary attacks. For a resource-constrained SIP UA, the proposed scheme delegates cryptographically computational operations like an exponentiation operation to the SIP server so that it is more efficient than the existing schemes in terms of energy consumption on the UA. Furthermore, it allows the proposed scheme to be easily applied to the deployed SIP networks since it does not require major modification to the signaling path associated with current SIP standard.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.463-472
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• 2012

This paper propose a security method that performs mutual authentication between the SIP UA and the server, check for integrity of the signaling channel and protection of SDP information for VoIP using a One-Time Password. To solve the vulnerability of existing HTTP Digest authentication scheme in SIP, Various SIP Authentication schemes have been proposed. But, these schemes can't meet security requirements of SIP or require expensive cryptographic operations. Proposed method uses OTP that only uses hash function and is updated each authentication. So Proposed method do not require expensive cryptographic operations but performs user authentication efficiently and safely than existing methods. In addition, Proposed method verifies the integrity of the SIP messages and performs SDP encryption/decryption through OTP that used for user authentication. So Proposed method can reduce communication overhead when applying S/MIME or TLS.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.5
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• pp.987-997
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• 2012

A Point-of-Sales (POS) terminal manages the selling process by a salesperson accessible interface in real time. Using a POS system makes a business and customer management much more efficient. For these reasons, many store install POS terminal and used it. But it has many problem that stealing personal information by hacking and insider corruption. Because POS system stored payment information like that sales information, card valid period, and password. In this paper, I proposed software integrity verification technique in POS system based on White list. This method can prevent accidents that personal information leak by hacking and POS system forge and falsification. This proposed method provides software integrity, so it can prevent inside and outside threats in advance.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.6
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• pp.1271-1282
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• 2012

Recently, security incidents occur continuously, resulting in the leakages of a large amount of the company's confidential and private information. For these reasons, the security technologies such as the authentication and the access control in order to prevent the information leakage are attracting attention. In particular, location-based authentication that utilizes the user's current location information which is used an authentication factor. And it provides more powerful authentication by controlling the users who attempt to access and blocks internal information leakage path. However, location information must be handled safely since it is the personal information. The location based authentication scheme proposed in this paper enhances the stability of the process location information compared with existing relevant location-based authentication protocol. Also it strengthens the end-user authentication by using one-time password. In addition, the proposed scheme provides authentication to prevent information leakage and employs the concept of the user's physical access control. Resultingly, the proposed scheme can provide higher security than the previous studies, while guarantee to low communication cost.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.6
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• pp.1345-1354
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• 2012

The modern society with the wide spread USB memory, witnesses the acceleration in the development of USB products that applied secure technology. Secure USB is protecting the data using the method as device-based access control, encryption of stored files, and etc. In terms of forensic analyst, to access the data is a lot of troubles. In this paper, we studied software-based data en/decryption technology and proposed for analysis mechanism to validation vulnerability that secured on removable storage media. We performed a vulnerability analysis for USB storage device that applied security mechanism. As a result, we found vulnerabilities that extracts a source file without a password.