26568006
Defense Mechanism for Information and Communication Infrastructure
701944
Simulation-Based Security Testing for Continuity of Essential Service
One of the most important characteristic of essential service in the computer network is its continuity. If the continuity of essential service is not guaranteed, it causes a big problem in normal operation of computer network. In our research, we suggest the simulation-based security testing for the continuity of essential service. Especially, the security testing sequence and Experimental Frame is designed to get indexes related to the continuity of essential service. We choose three testing indexes that represent the degree of service continuity and testing methods to get those indexes. Also, to explain the indexes and the testing methods, two testing examples are presented.
30809053
Vulnerability Assessment Simulation for Information Infrastructure Protection
The main contribution of this research is to present the method that make it possible to assess the vulnerability in the information infrastructure using simulation technology. To construct the vulnerability assessment simulation system, we make use of the knowledge-based simulation modeling methodology and we designed expressions to estimate the degree of vulnerability of host. Also, we show newly defined vulnerability analysis method that is applicable to vulnerability assessment simulation system. As research results, the vulnerability assessment simulation system and VDBFS(Vulnerability DataBase For Simulator) are constructed.
14176330
System Specification Based Network Modeling for Survivability Testing Simulation
As the structure and behavior of computer network becomes complicated and unpredictable, it becomes difficult to test the survivability of network. The modeling and simulation is a widely used approach to predict the behavior of system or set of system. In this research, we apply a modeling methodology to construct the valid model of computer network focusing on its vulnerability for survivability testing. To accomplish our aim, the appropriate modeling method should be defined. Especially, we take advantage of the system specification based modeling approach to construct valid network model.
15684093
Efficient Authentication and Authorization of Mobile Users Based on Peer-to-Peer Network Mechanisms
This paper presents a peer-to-peer based authentication and authorization infrastructure to minimize authentication delays when mobile users roam across different wireless networks. The basic idea is to avoid exchanging security information between networks visited by a roaming user and the user's home authentication, authorization, and accounting (AAA) server that is typically located in the home network possibly far away from the visited network. Instead, authentication and authorization of a roaming user shall be supported by an AAA server in the visited network. We propose that the AAA server that is responsible for authentication and authorization in a newly visited network locates the AAA server in the previously visited network and retrieves the required security information from that AAA server. The AAA servers can be organized in a peer-to-peer manner and peer-to-peer mechanisms can be applied for searching and transferring security information between them. We propose several mechanisms for quickly locating the previously responsible AAA server in order to decrease authentication delays. The performance of these mechanisms is evaluated by simulations. Real performance measurements show the rather low performance overhead of application level forwarding used in peer-to-peer networks.
15273022
Open Location-Based Service Using Secure Middleware Infrastructure in Web Services
Location-based services or LBS refers to value-added service by processing information utilizing mobile user location. For this kind of LBS, the role of security service is very important in the LBS that store and manage the location information of mobile devices and support various application services using those location information. And in all phases of these functions that include acquisition of location information, storage and management of location information, user management including authentication and information security, and management of the large-capacity location information database, safe security service must be provided. We show the security methods for open LBS in this paper.
13287397
An analysis of the performance impact of wrong-path memory references on out-of-order and runahead execution processors
High-performance, out-of-order execution processors spend a significant portion of their execution time on the incorrect program path even though they employ aggressive branch prediction algorithms. Although memory references generated on the wrong path do not change the architectural state of the processor, they affect the arrangement of data in the memory hierarchy. This paper examines the effects of wrong-path memory references on processor performance. It is shown that these references significantly affect the IPC (instructions per cycle) performance of a processor. Not modeling them leads to errors of up to 10 percent (4 percent on average) in IPC estimates for the SPEC CPU2000 integer benchmarks on an out-of-order processor and errors of up to 63 percent on a runahead-execution processor. In general, the error in the IPC increases with increasing memory latency and instruction window size. We find that wrong-path references are usually beneficial for performance because they prefetch data that is used by later correct-path references. L2 cache pollution is found to be the most significant negative effect of wrong-path references. Code examples are shown to provide insights into how wrong-path references affect performance. We also show that it is crucial to model wrong-path references to accurately estimate the performance improvement provided by runahead execution.
6231139
Practical and Provably-Secure Multicasting over High-Delay Networks
This paper considers the problem of authenticated key exchange in a dynamic group in which members join and leave the group in an arbitrary fashion. A group key exchange scheme for such a dynamic group is designed to minimize the cost of the rekeying operations associated with group updates. Although a number of schemes have attempted for many years to address this problem, all provably-secure schemes are inadequate in dealing with a dynamic group where group members are spread across a wide area network; their communication overhead for group rekeying is significant in terms of the number of communication rounds or the number of messages, both of which are recognized as the dominant factors that severely slow down group key exchange over a wide area network. In this paper, we propose an efficient key exchange scheme for this scenario and prove its security against an active adversary under the factoring assumption. The proposed scheme requires only a constant number of rounds while achieving low message complexity.
3140924
Binary halftone image resolution increasing by decision tree learning
This paper presents a new, accurate, and efficient technique to increase the spatial resolution of binary halftone images. It makes use of a machine learning process to automatically design a zoom operator starting from pairs of input-output sample images. To accurately zoom a halftone image, a large window and large sample images are required. Unfortunately, in this case, the execution time required by most of the previous techniques may be prohibitive. The new solution overcomes this difficulty by using decision tree (DT) learning. Original DT learning is modified to obtain a more efficient technique (WZDT learning). It is useful to know, a priori , sample complexity (the number of training samples needed to obtain, with probability 1-/spl delta/, an operator with accuracy /spl epsiv/): we use the probably approximately correct (PAC) learning theory to compute the sample complexity. Since the PAC theory usually yields an overestimated sample complexity, statistical estimation is used to evaluate, a posteriori, a tight error bound. Statistical estimation is also used to choose an appropriate window and to show that DT learning has good inductive bias. The new technique is more accurate than a zooming method based on simple inverse halftoning techniques. The quality of the proposed solution is very close to the theoretical optimal obtainable quality for a neighborhood-based zooming process using the Hamming distance to quantify the error.