• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.2
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• pp.179-192
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• 2024

macOS presents challenges for memory data acquisition due to its proprietary system architecture, closed-source kernel, and security features such as System Integrity Protection (SIP), which are exclusive to Apple's product line. Consequently, conventional memory acquisition tools are often ineffective or require system rebooting. This paper analyzes the status and limitations of existing memory forensics research and tools related to macOS. We investigate methods for memory acquisition and analysis across various macOS versions. Our findings include the development of a practical memory acquisition and analysis process for digital forensic investigations utilizing OSXPmem and dd tools for memory acquisition without system rebooting, and Volatility 2, 3 for memory data analysis.

• Journal of Information Technology Services
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• v.10 no.3
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• pp.237-250
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• 2011

Recently, Wireless Sensor Networks (WSN) require energy performance and guaranteed delivery delay time, contrarily with previous MAC protocols that aim to high throughput mostly. In order to satisfy the new significant requirements, many MAC protocols of WSN employ and try to enhance the duty cycle mechanism which is energy efficient technique in MAC layer. This duty cycle mechanism is oriented by toggling the transceiver conditions composed of wakeup and sleep states. The synchronous MAC protocols perform the period synchronization process. Hence, these are energy efficient in periodic monitoring environment, but are inefficient in where an event is incurred rarely and infrequently. Otherwise, the performance of asynchronous MAC protocols are contrarily with synchronous protocols. In this paper, we design two models consisting Always-busy and Always-idle ti simplify the general network congestion conditions. Through these models, moreover, we analyze two types MAC protocols in terms of energy efficiency and delay performance by analytical results. Additionally, we also evaluate two MAC protocols with two gongestion models that we designed. By the analytical and simulated results, we provide the general and efficient decision method in which protocols are more appropriate in a certain WSN environment.

• Convergence Security Journal
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• v.11 no.1
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• pp.3-10
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• 2011

This paper proposes DPA(Dynamic Priority Assignment) MAC protocol to improve the traffic QoS on the HFC-CATV(Hybrid Fiber Coax CAble TeleVision) network. In results, DPA MAC protocol is the best performance compare with to IEEE 802.14a MAC in mean request delay, mean access delay. Also, the paper prove a reliability of proposed protocol through comparison between performance analysis and simulation result of DAP MAC protocol.

• The KIPS Transactions:PartC
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• v.17C no.4
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• pp.335-346
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• 2010

Mac OS X is the Computer Operating System that develop in Apple Inc. Mac OS X is the successor to Mac OS 9 Version which had been Apple's primary operating system since 1984. Recently, Mac OS X 10.6 (Snow Leopard) has been manufactured and is distributed to user. Apple's Mac OS X Operating System is occupying about 10% in the world Operating System market share. But, Forensic tools that is utilized on digital forensic investigation can not forensic analysis about Mac OS X properly. To do forensic investigation about Mac OS X, information connected with user's action and trace can become important digital evidence in Operating System. This paper presents way about user trace data acquisition methodology in Mac OS X.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12A
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• pp.1329-1338
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• 2007

Leading MAC protocols developed for duty-cycled WSNs such as B-MAC employ a long preamble and channel sampling. The long preamble introduces excess latency at each hop and suffers from excess energy consumption at non-target receivers. In this paper we propose AS-MAC (Asynchronous Sensor MAC), a low power MAC protocol for wireless sensor networks (WSNs). AS-MAC solves these problems by employing a series of preload approach that retains the advantages of low power listening and independent sleep schedule. Moreover AS-MAC offers an additional advantage such as flexible duty cycle as data rate varies. We demonstrate that AS-MAC is better performance than B-MAC through analysis and evaluation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10A
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• pp.877-885
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• 2005

The Home Phoneline Networking Alliance (HomePNA) 2.0 technology can establish a home network using existing in-home phone lines, which provides a channel rate of 4-32 Mbps. HomePNA 2.0 Medium Access Control(MAC) protocol adopts an IEEE 802.3 Carrier Sense Multiple Access with Collision Detection (CSMA/CD) access method, Quality of Service(QoS) algorithm, and Distributed Fair Priority Queuing(DFPQ) collision resolution algorithm. In this paper, we propose some mathematical models about the important elements of HomePNA 2.0 MAC protocol performance, which are Saturation Throughput, Packet Delay and Packet Jitter. Then, we present an overall performance analysis of HomePNA 2.0 MAC protocol along with simulations.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.166-168
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• 2010

본 논문에서는 TMAC 환경에서 취약성 분석하였다. T-MAC의 보안 특성은 S-MAC 통신 프로토콜이 갖는 보안 취약성과 동일한 형태이다. T-MAC 통신은 TA가 도입된 것을 제외하면, S-MAC에서 강조하고 있는 동일한 보안 인증방안이 필요함을 확인할 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.99-103
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• 2006

In this paper, we focus on the problem of designing an energy efficient MAC protocol for wireless sensor networks and analyze S(Sensor)-MAC and T(Time-out)-MAC. S-MAC is based on the concept of the 'listen/sleep mode cycle'. This applies message passing to reduce contention latency for sensor-network applications that require store-and-forward processing as data moves through the network. However unlike the S-MAC, where the duration of the cycle is fixed, T-MAC introduces an adaptive duty cycle in a novel way: by dynamical ending the active part of it. This reduces the amount of energy wasted on idle listening, in which nodes wait for potentially incoming messages while still maintaining a reasonable throughput. In this paper we discuss the design of these two Protocols. We analyze them from the aspect of latency, throughput, and power savings when using the OMNeT++ simulator in various environments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.6
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• pp.1668-1688
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• 2012

Cooperative communications and network coding schemes have been proposed to increase system throughput for ad hoc networks. In this paper, we present throughput and delay analysis of the new network coding-enabled cooperative MAC protocol called NC-MAC, which has been proposed by us in order to significantly enhance system performance. This protocol introduces an approach that can accommodate both cooperative communication and network coding for wireless ad hoc networks by slightly increasing overhead and modifying standards. The protocol's performance is evaluated using mathematical analysis and computer simulation and two performance measures, system throughput and average channel access delay, are used for a performance comparison with previous schemes. It is assumed that all the frames exchanged over a wireless channel are susceptible to transmission errors, which is a new but more reasonable assumption differentiating this research from previous research. Numerical results show this protocol provides significantly enhanced system performance compared with conventional cooperative MAC protocols used in previous research. For instance, system performance is 47% higher using the NC-MAC protocol than when using the rDCF protocol.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.469-471
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• 2002

This paper presents analysis of the IEEE802.11 MAC protocol and implementation of the asynchronous communication portion of the IEEE802.11 MAC protocol. we have used PRISM2 chipsets from intertsil to build physical layer and PCI controller from PLX to interface LLC layer. This study is shown to be able to apply to MAC implementation in high speed LAN.