• Journal of IKEEE
• /
• v.26 no.4
• /
• pp.622-627
• /
• 2022

This paper proposes an intrusion detection system for in-vehicle network to improve detection performance considering attack counts and attack types. In intrusion detection system, both FNR (False Negative Rate), where intrusion frame is misjudged as normal frame, and FPR (False Positive Rate), where normal frame is misjudged as intrusion frame, seriously affect vechicle safety. This paper proposes a novel intrusion detection algorithm to improve both FNR and FPR, where data frame previously detected as intrusion above certain attack counts is automatically detected as intrusion and the automatic intrusion detection method is adaptively applied according to attack types. From the simulation results, the propsoed method effectively improve both FNR and FPR in DoS(Denial of Service) attack and spoofing attack.

• Structural Engineering and Mechanics
• /
• v.82 no.4
• /
• pp.517-542
• /
• 2022

The effect of mean angle of wind attack on the flutter critical wind speed of two generic bridge deck cross-sections, viz, one closed box type streamlined section (deck-1) and closed box trapezoidal bluff type section with extended flanges/overhangs (deck-2) type of section have been studied using Computational Fluid Dynamics (CFD) based forced vibration simulation method. Owing to the importance of the effect of the amplitude of forcing oscillation on the flutter onset, its effect on the flutter derivatives and flutter onset have been studied, especially at non-zero mean angles of wind attack. The flutter derivatives obtained have been used to evaluate flutter critical wind speeds and flutter index of the deck sections at non-zero mean angles of wind attack studied and the same have been validated with those based on experimental results reported in literature. The value of amplitude of forcing oscillation in torsional degree of freedom for CFD based simulations is suggested to be in the range of 0.5° to 2°, especially for bluff bridge deck sections. Early onset of flutter from numerical simulations, thereby conservative estimate of occurrence of instability has been observed from numerical simulations in case of bluff bridge deck section. The study aids in gaining confidence and the extent of applicability of CFD during early stages of bridge design, especially towards carrying out studies on mean incident wind effects.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.3
• /
• pp.467-476
• /
• 2017

In this paper, we analyze Generalized Feistel Network(GFN) Type I, Type II, Type III that round function use SP update function, secret S-box and $k{\times}k$ MDS matirx. In this case an attacker has no advantage about S-box. For each type of GFN, we analyze and restore secret S-box in 9, 6, 6 round using the basis of integral cryptanalysis with chosen plaintext attack. Also we restore secret S-box in 16 round of GFN Type I with chosen ciphertext attack. In conclusion, we need $2^{2m}$ data complexity and ${\frac{2^{3m}}{32k}},{\frac{2^{3m}}{24k}},{\frac{2^{3m}}{36k}}$ time complexity to restore m bit secret S-box in GFN Type I, Type II, Type III.

• The KIPS Transactions:PartC
• /
• v.12C no.5 s.101
• /
• pp.633-642
• /
• 2005

Ubiquitous computing system is about networked processors, which is constructed with one or more computers interconnected by the networks. However, traditional security solution lacks a Proactive maintenance technique because of its focusing on developing the qualitative detection and countermeasure after attack. Thus, in this paper, we propose a quantitative assessment modeling technique, by which the general infrastructure can be improved and the attacks on a specific infrastructure be detected and protected. First of all, we develop the definition of survivality and modeling technique for quantitative assessment modeling with the static information on the system random information, and attack-type modeling. in addition, the survivality analysis on TCP-SYN attack and code-Red worm attack is performed for validating the proposed technique.

• Wind and Structures
• /
• v.32 no.5
• /
• pp.509-520
• /
• 2021

The streamlined box is a common type of girders for long-span suspension bridges. Spanning deep canyons, long-span bridges are frequently attacked by strong winds with large angles of attack. In this situation, the flow field around the streamlined box changes significantly, leading to reduction of the flutter performance. The wind fairings have different effects on the flutter performance. Therefore, this study examines the flutter performance of box girders with different wind fairings at large angles of attack. Computational fluid dynamics (CFD) simulations were carried out to extract the flutter derivatives, and the critical flutter state of a long-span bridge was determined. Further comparisons of the wind fairings were investigated by a rapid method which is related to the input energy by the aerodynamic force. The results show that a reasonable type of wind fairings could improve the flutter performance of long-span bridges at large angles of attack. For the torsional flutter instability, the wind fairings weaken the adverse effect of the vortex attaching to the girder, and a sharper one could achieve a better result. According to the input energies on the girder with different wind fairings, the symmetrical wind fairings are more beneficial to the flutter performance

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.14 no.5
• /
• pp.69-78
• /
• 2004

The change of attack techniques paradigm was begun by fast extension of the latest Internet and new attack form appearing. But, Most intrusion detection systems detect only known attack type as IDS is doing based on misuse detection, and active correspondence is difficult in new attack. Therefore, to heighten detection rate for new attack pattern, the experiments to apply various techniques of anomaly detection are appearing. In this paper, we propose an behavior profiling method using Bayesian framework based on graphics from audit data and visualize behavior profile to detect/analyze anomaly behavior. We achieve simulation to translate host/network audit data into BF-XML which is behavior profile of semi-structured data type for anomaly detection and to visualize BF-XML as SVG.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.15 no.1
• /
• pp.57-66
• /
• 2005

SHACAL-2 is a 256-bit block cipher with various key sizes based on the hash function SHA-2. Recently, it was recommended as one of the NESSIE selections. This paper presents differential-linear type attacks on SHACAL-2 with 512-bit keys up to 32 out of its 64 rounds. Our 32-round attack on the 512-bit keys variants is the best efficient attack on this cipher in published literatures.

• Journal of Information Processing Systems
• /
• v.14 no.6
• /
• pp.1431-1437
• /
• 2018

Securing objects in the Internet of Things (IoT) is essential. Authentication model is one candidate to secure an object, but it is only limited to handle a specific type of attack such as Sybil attack. The authentication model cannot handle other types of attack such as trust-based attacks. This paper proposed two-phase security protection for objects in IoT. The proposed method combined authentication and statistical models. The results showed that the proposed method could handle other attacks in addition to Sybil attacks, such as bad-mouthing attack, good-mouthing attack, and ballot stuffing attack.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.9
• /
• pp.393-398
• /
• 2013

This paper introduces a new collision attack on first-order masked AES. This attack is a known plaintext attack, while the existing collision attacks are a chosen plaintext attack. In addition, our method is more efficient than the second-order power analysis and requires about 1/27.5 power measurements by comparison with the last collision attack. Some experiment results of this paper support this fact. In this paper, we also introduce a simple countermeasure, which can protect against our attack.

• International Journal of Computer Science & Network Security
• /
• v.21 no.8
• /
• pp.1-12
• /
• 2021

An operation of an organization is currently using a digital environment which opens to potential cyber-attacks. These phenomena become worst as the cyberattack landscape is changing rapidly. The impact of cyber-attacks varies depending on the scope of the organization and the value of assets that need to be protected. It is difficult to assess the damage to an organization from cyberattacks due to a lack of understanding of tools, metrics, and knowledge on the type of attacks and their impacts. Hence, this paper aims to identify domains and sub-domains of cyber-attack taxonomy to facilitate the understanding of cyber-attacks. Four phases are carried in this research: identify existing cyber-attack taxonomy, determine and classify domains and sub-domains of cyber-attack, and construct the enhanced cyber-attack taxonomy. The existing cyber-attack taxonomies are analyzed, domains and sub-domains are selected based on the focus and objectives of the research, and the proposed taxonomy named AVOIDITALS Cyber-attack Taxonomy is constructed. AVOIDITALS consists of 8 domains, 105 sub-domains, 142 sub-sub-domains, and 90 other sub-sub-domains that act as a guideline to assist administrators in determining cyber-attacks through cyber-attacks pattern identification that commonly occurred on digital infrastructure and provide the best prevention method to minimize impact. This research can be further developed in line with the emergence of new types and categories of current cyberattacks and the future.