• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.5
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• pp.54-62
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• 2007

We propose a novel authentication protocol for wireless mesh network. The proposed authentication protocol is based on the password scheme for convenience of users. The proposed protocol is evaluated through three analyses. The correctness of the proposed protocol is proved using the GNY analysis. By the security analysis, we show that the proposed protocol is resistant to various attacks. For the performance analysis, we implemented the protocol in Linux operating system based laptop and measured the transmission time. The analytic results show that the proposed protocol provides the secure wireless mesh network without considerable performance degradation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.3
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• pp.417-429
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• 2013

A lot of OS(Operating Systems) such as Linux and Android selected Ext4 as the official file system. Therefore, a recovery of deleted file from Ext4 is becoming a pending issue. In this paper, we suggest how to recover the deleted file by analyzing the entire structure of Ext4 file system, the study of metadata area, the distinct feature when file is assigned and deleted. Particularly, we focus on studying the features of file which is assigned in Ext4 file system in Android OS and also suggest the method to recover the deleted file that is fragmented from the un-allocated area.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.77-91
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• 2019

Recent Linux operating systems having been increasingly used, ranging from automotive consoles, CCTV, IoT devices, and mobile devices to various versions of the kernel. Because these devices can be used as strong evidence in criminal investigations, there is a risk of destroying evidence through file deletion. Ext filesystem forensics has been studied in depth because it can recovery deleted files without depending on the kind of device. However, studies have been carried out without consideration of characteristics of file system which may vary depending on the kernel. This problem can lead to serious situations, such as those that can impair investigative ability and cause doubt of evidence ability, when an actual investigation attempts to analyze a different version of the kernel. Because investigations can be performed on various distribution and kernel versions of Linux file systems at the actual investigation site, analysis of the metadata changes that occur when files are deleted by Linux distribution and kernel versions is required. Therefore, in this paper, we analyze the difference of metadata according to the Linux kernel as a solution to this and recovery deleted file. After that, the investigating agency needs to consider the metadata change caused by the difference of Linux kernel version when performing Ext filesystem forensics.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.5
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• pp.2084-2100
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• 2020

Operating system (OS) kernel function call graphs have been widely used in OS analysis and defense. However, most existing methods and tools for generating function call graphs are designed for application programs, and cannot be used for generating OS kernel function call graphs. This paper proposes a virtualization-based call graph generation method called Acquire in Trap (AIT). When target kernel functions are called, AIT dynamically initiates a system trap with the help of a virtualization technique. It then analyzes and records the calling relationships for trap handling by traversing the kernel stacks and the code space. Our experimental results show that the proposed method is feasible for both Linux and Windows OSs, including 32 and 64-bit versions, with high recall and precision rates. AIT is independent of the source code, compiler and OS kernel architecture, and is a universal method for generating OS kernel function call graphs.

• Journal of KIISE
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• v.44 no.4
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• pp.352-362
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• 2017

This paper analyzes security threats in Security Enhanced (SE) Android and proposes a new technique to efficiently protect application data including private information on rooted Android phones. On an unrooted device, application data can be accessed by the application itself according to the access control models. However, on a rooted device, a root-privileged shell can disable part or all of the access control model enforcement procedures. Therefore, a root-privileged shell can directly access sensitive data of other applications, and a malicious application can leak the data of other applications outside the device. To address this problem, the proposed technique allows only some specific processes to access to the data of other applications including private information by modifying the existing SEAndroid Linux Security Module (LSM) Hook function. Also, a new domain type of process is added to the target system to enforce stronger security rules. In addition, the proposed technique separates the directory type of a newly installed application and the directory type of previously installed applications. Experimental results show that the proposed technique can effectively protect the data of each application and incur performance overhead up to or less than 2 seconds.

• Convergence Security Journal
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• v.10 no.2
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• pp.37-41
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• 2010

The object of this paper is to design a embedded system based on sensor networks. The proposed system can manage the heating by sensing and analyzing the temperature and humidity in apartment house and others. For implementing this system, we devide JAVA API into the platform-independent JAVA part and platform-dependent native part for the implementation of JAVA API to manage the linux based embedded system devices, and focus on the control of the embedded system devices using JAVA API.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.2
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• pp.55-70
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• 2006

In this paper, we propose a new access control security architecture for supporting flexibility in Secure Operating Systems. By adding virtual access control system layer to the proposed security architecture, various access control models such as MAC, DAC, and RBAC can be applied to Secure Operating Systems easily. The proposed security architecture is designed to overcome the problem of Linux system's base access control system. A policy manager can compose various security models flexibly and apply them to Operating Systems dynamically. Also, the proposed architecture is composed of 3 modules such as access control enforcement, access control decision, and security control. And access control models are abstracted to hierarchy structure by virtual access control system. And, we present the notation of policy conflict and its resolution method by applying various access control model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3086-3092
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• 2014

The FTP that provides file transfer capabilities to/from another station cannot provides data confidentialities. The FTPS and SFTP can support a security functionalities. The FTPS needs a SSL layer and SFTP use a functions of SSH. And therefore the FTPS or SFTP needs an additional modules such as SSL or SSH. In this paper, we propose a new Secured FTP protocol that can support the security functions without extra security system. The Secured FTP uses Diffie-Hellman key agreement algorithm for shared secret key generation and AES-Counter algorithm for data encryption algorithm. Our designed Secured FTP is implemented in Linux environments and the proper operations of implemented Secured FTP is verified.

• Journal of the Korea Society of Computer and Information
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• v.10 no.2 s.34
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• pp.105-112
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• 2005

As the development of information telecommunication technology and thus the information sharing and opening is accelerated, If system is exposed to various threatener and the avrious security incident is rasing its head with social problem. As countermeasure, to protect safely and prepare in the attack for a system from a be latent security threat, various security systems are been using such as IDS, Firewall, VPN etc.. But, expertise or expert is required to handle security system. The module, implemented in this paper, is based on Windows XP, like Linux and Unix, and has effect integrity and non-repudiation for a file.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.540-543
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• 2004

Address Resolution Protocol (ARP) cache poisoning is a MAC layer attack that can only be carried out when an attacker is connected to the same local network as the target machines. ARP is not a new problem, but wireless network introduces a new attack point and more vulnerable to the attack. The attack on wireless network cannot be detected by current detection tool installed on wired network. In order to detect the ARP poisoning attack, there must be a ARP poisoning detection tool for wireless LAN environment. This paper proposes linux-based ARP poisoning detection system equipped with wireless LAN card and Host AP device driver