Seong-Moo Yoo

Black hole attack in mobile Ad Hoc networks

The black hole problem is one of the security attacks that occur in mobile ad hoc networks (MANETs). We present two possible solutions. The first is to find more than one route to the destination. The second is to exploit the packet sequence number included in any packet header. Computer simulation shows that compared to the original ad hoc on-demand distance vector (AODV) routing scheme, the second solution can verify 75% to 98% of the route to the destination depending on the pause times at a minimum cost of the delay in the networks.

Use of Artificial Color filtering to improve iris recognition and searching

Iris recognition and searching are attractive in biometrics for many reasons. The spatial patterns have been studied and recognized effectively for several years. They are more complex than fingerprints. We suggest here that the relatively new field of Artificial Color filtering can provide an orthogonal discriminant to the spatial pattern discriminant. We also show how to combine results from the two discriminants in such a way as to improve performance of the combined system over either part-something that has been troubling until now.

Passive Benign Worm Propagation Modeling with Dynamic Quarantine Defense

Worm attacks can greatly distort network performance, and countering infections can exact a heavy toll on economic and technical resources. Worm modeling helps us to better understand the spread and propagation of worms through a network, and combining effective types of mitigation techniques helps prevent and mitigate the effects of worm attacks. In this paper, we propose a mathematical model which combines both dynamic quarantine and passive benign worms. This Passive Worm Dynamic Quarantine (PWDQ) model departs from previous models in that infected hosts will be recovered either by passive benign worms or quarantine measure. Computer simulation shows that the performance of our proposed model is significantly better than existing models, in terms of decreasing the number of infectious hosts and reducing the worm propagation speed.

Artificial color image logic

Artificial Color is simply biomimetic spectral sensing and processing to achieve spectral discrimination. Using Artificial Color means to construct image plane filters; we can then perform logic operations on those filters before applying them to scenes. Boolean and fuzzy logic can both be used. We illustrate the concept by the Boolean AND of two such masks applied to a complex scene.

An efficient task allocation scheme for two-dimensional mesh-connected systems

Efficient allocation of proper size submeshes to incoming tasks in two-dimensional (2D) mesh-connected processors is very important for achieving the desired high performance. It also needs to guarantee the recognition of the free submeshes with minimum overhead. In this paper we present an efficient task allocation scheme for 2D meshes. By employing a new approach for searching the array, our scheme can find the available submesh without the scanning of the entire 2D array unlike earlier designs. As a result, our scheme can significantly reduce the task allocation time. Comprehensive computer simulation reveals that the average allocation time and waiting delay are much smaller than earlier schemes irrespective of the size of meshes. The hardware overhead is comparable to other schemes.

An efficient reliable one-hop broadcast in mobile ad hoc networks

A reliable one-hop broadcast is a fundamental communication primitive in mobile ad hoc networks in which a message from the source node is guaranteed to be delivered to all nodes within the source nodes transmission range. Despite the importance of it, reliable one-hop broadcast is not easy to accomplish due to collisions in wireless networks known as Hidden Terminal Problem. This paper presents a MAC protocol that not only guarantees reliable one-hop broadcast but also achieves it efficiently by exploring as many simultaneous executions of the communication as possible. In addition to the data packets, the proposed algorithm utilizes the control packets that prevent packet collisions, and at the same time, make the simultaneous communications possible to improve the network throughput. Simulation results show the effectiveness of the proposed algorithm.

The Insecurity of Wireless Networks

Wi-Fi is the standard protocol for wireless networks used extensively in US critical infrastructures. Since the Wired Equivalency Privacy (WEP) security protocol was broken, the Wi-Fi Protected Access (WPA) protocol has been considered the secure alternative compatible with hardware developed for WEP. However, in November 2008, researchers developed an attack on WPA, allowing forgery of Address Resolution Protocol (ARP) packets. Subsequent enhancements have enabled ARP poisoning, cryptosystem denial of service, and man-in-the-middle attacks. Open source systems and methods (OSSM) have long been used to secure networks against such attacks. This article reviews OSSMs and the results of experimental attacks on WPA. These experiments re-created current attacks in a laboratory setting, recording both wired and wireless traffic. The article discusses methods of intrusion detection and prevention in the context of cyberphysical protection of critical Internet infrastructure. The basis for this research is a specialized (and undoubtedly incomplete) taxonomy of Wi-Fi attacks and their adaptations to existing countermeasures and protocol revisions. Ultimately, this article aims to provide a clearer picture of how and why wireless protection protocols and encryption must achieve a more scientific basis for detecting and preventing such attacks.

A performance simulation for route maintenance in wireless ad hoc networks

A routing protocol in ad hoc wireless networks must take special consideration to link failure and route maintenance in order that the network services will not be interrupted. To decrease the link failure, Anticipated Route Maintenance Protocol (ARM) has been proposed. However, the detailed performance for this protocol has not been evaluated. In this paper, we have compared the performance of two protocols, standard Dynamic Source Routing Protocol (DSR) and a combination of DSR and ARM. The simulation results show how ARM improves the functionality of DSR by preventing the links in the route from breaking. Packets delivery ratio could be increased using ARM maintenance and achieved approximately 100% improvement. The simulations clarify also how ARM shows a noticeable improvement in dropped packets and links stability over DSR, even though there is more traffic and channel overhead in ARM.

Recycled path routing in mobile ad hoc networks

In mobile ad hoc networks, many routing algorithms rely on some form of flooding to accomplish the route discovery process. Flooding, however, consumes many valuable network resources such as time, bandwidth, and power. Most current routing schemes expire valid routes after a time period to account for nodal movement. This paper proposes a new route discovery method, called recycled path routing (RPR), which directs broadcasts toward the destination node even in the absence of location information. The recycled path routing scheme reduces the search space for the destination node by implementing an expired route cache that is utilized by each node in the network. Routes are added to the expired route cache as they expire from the active route cache and remain there until some time interval has passed or a new route has been discovered. Since these expired routes can provide valuable insight into finding new routes, RPR uses them to direct broadcasts toward the destination node. RPR can save a significant quantity of valuable network resources because only nodes near the optimal path will rebroadcast route requests.

Dynamic task scheduling and allocation for 3D torus multicomputer systems

Multicomputer systems achieve high performance by utilizing a number of computing nodes. Multidimensional meshes have become popular as multicomputer architectures due to their simplicity and efficiency. In this paper we propose an efficient processor allocation scheme for 3D torus based on first-fit approach. The scheme minimizes the allocation time by effectively manipulating the 3D information as 2D information using CST (Coverage Status Table). Comprehensive computer simulation reveals that the allocation time of the proposed scheme is always smaller than the earlier scheme based on best-fit approach, while allowing comparable processor utilization. The difference gets more significant as the input load increases. To investigate the performance of the proposed scheme with different scheduling environment, non-FCFS scheduling policy along with the typical FCFS policy is also studied.